class Net::IMAP

Net::IMAP implements Internet Message Access Protocol (IMAP) client functionality. The protocol is described in IMAP4rev1 [RFC3501] and IMAP4rev2 [RFC9051].

IMAP Overview

An IMAP client connects to a server, and then authenticates itself using either authenticate or login. Having authenticated itself, there is a range of commands available to it. Most work with mailboxes, which may be arranged in an hierarchical namespace, and each of which contains zero or more messages. How this is implemented on the server is implementation-dependent; on a UNIX server, it will frequently be implemented as files in mailbox format within a hierarchy of directories.

To work on the messages within a mailbox, the client must first select that mailbox, using either select or examine (for read-only access). Once the client has successfully selected a mailbox, they enter the “selected” state, and that mailbox becomes the current mailbox, on which mail-item related commands implicitly operate.

Sequence numbers and UIDs

Messages have two sorts of identifiers: message sequence numbers and UIDs.

Message sequence numbers number messages within a mailbox from 1 up to the number of items in the mailbox. If a new message arrives during a session, it receives a sequence number equal to the new size of the mailbox. If messages are expunged from the mailbox, remaining messages have their sequence numbers “shuffled down” to fill the gaps.

To avoid sequence number race conditions, servers must not expunge messages when no command is in progress, nor when responding to fetch, store, or search. Expunges may be sent during any other command, including uid_fetch, uid_store, and uid_search. The noop and idle commands are both useful for this side-effect: they allow the server to send all mailbox updates, including expunges.

UIDs, on the other hand, are permanently guaranteed not to identify another message within the same mailbox, even if the existing message is deleted. UIDs are required to be assigned in ascending (but not necessarily sequential) order within a mailbox; this means that if a non-IMAP client rearranges the order of mail items within a mailbox, the UIDs have to be reassigned. An IMAP client thus cannot rearrange message orders.

Examples of Usage

List sender and subject of all recent messages in the default mailbox

imap = Net::IMAP.new('mail.example.com')
imap.authenticate('PLAIN', 'joe_user', 'joes_password')
imap.examine('INBOX')
imap.search(["RECENT"]).each do |message_id|
  envelope = imap.fetch(message_id, "ENVELOPE")[0].attr["ENVELOPE"]
  puts "#{envelope.from[0].name}: \t#{envelope.subject}"
end

Move all messages from April 2003 from “Mail/sent-mail” to “Mail/sent-apr03”

imap = Net::IMAP.new('mail.example.com')
imap.authenticate('PLAIN', 'joe_user', 'joes_password')
imap.select('Mail/sent-mail')
if not imap.list('Mail/', 'sent-apr03')
  imap.create('Mail/sent-apr03')
end
imap.search(["BEFORE", "30-Apr-2003", "SINCE", "1-Apr-2003"]).each do |message_id|
  imap.copy(message_id, "Mail/sent-apr03")
  imap.store(message_id, "+FLAGS", [:Deleted])
end
imap.expunge

Capabilities

Most Net::IMAP methods do not currently modify their behaviour according to the server’s advertised capabilities. Users of this class must check that the server is capable of extension commands or command arguments before sending them. Special care should be taken to follow the capabilities requirements for starttls, login, and authenticate.

See capable?, auth_capable?, capabilities, auth_mechanisms to discover server capabilities. For relevant capability requirements, see the documentation on each IMAP command.

imap = Net::IMAP.new("mail.example.com")
imap.capable?(:IMAP4rev1) or raise "Not an IMAP4rev1 server"
imap.capable?(:starttls)  or raise "Cannot start TLS"
imap.starttls

if imap.auth_capable?("PLAIN")
  imap.authenticate "PLAIN", username, password
elsif !imap.capability?("LOGINDISABLED")
  imap.login username, password
else
  raise "No acceptable authentication mechanisms"
end

# Support for "UTF8=ACCEPT" implies support for "ENABLE"
imap.enable :utf8 if imap.capable?("UTF8=ACCEPT")

namespaces  = imap.namespace if imap.capable?(:namespace)
mbox_prefix = namespaces&.personal&.first&.prefix || ""
mbox_delim  = namespaces&.personal&.first&.delim  || "/"
mbox_path   = prefix + %w[path to my mailbox].join(delim)
imap.create mbox_path

Basic IMAP4rev1 capabilities

IMAP4rev1 servers must advertise IMAP4rev1 in their capabilities list. IMAP4rev1 servers must implement the STARTTLS, AUTH=PLAIN, and LOGINDISABLED capabilities. See starttls, login, and authenticate for the implications of these capabilities.

Caching CAPABILITY responses

Net::IMAP automatically stores and discards capability data according to the the requirements and recommendations in IMAP4rev2 §6.1.1, §6.2, and §7.1. Use capable?, auth_capable?, or capabilities to use this cache and avoid sending the capability command unnecessarily.

The server may advertise its initial capabilities using the CAPABILITY ResponseCode in a PREAUTH or OK greeting. When TLS has started (starttls) and after authentication (login or authenticate), the server’s capabilities may change and cached capabilities are discarded. The server may send updated capabilities with an OK TaggedResponse to login or authenticate, and these will be cached by Net::IMAP. But the TaggedResponse to starttls MUST be ignored–it is sent before TLS starts and is unprotected.

When storing capability values to variables, be careful that they are discarded or reset appropriately, especially following starttls.

Using IMAP4rev1 extensions

See the IANA IMAP4 capabilities registry for a list of all standard capabilities, and their reference RFCs.

IMAP4rev1 servers must not activate behavior that is incompatible with the base specification until an explicit client action invokes a capability, e.g. sending a command or command argument specific to that capability. Servers may send data with backward compatible behavior, such as response codes or mailbox attributes, at any time without client action.

Invoking capabilities which are unknown to Net::IMAP may cause unexpected behavior and errors. For example, ResponseParseError is raised when unknown response syntax is received. Invoking commands or command parameters that are unsupported by the server may raise NoResponseError, BadResponseError, or cause other unexpected behavior.

Some capabilities must be explicitly activated using the enable command. See enable for details.

Thread Safety

Net::IMAP supports concurrent threads. For example,

imap = Net::IMAP.new("imap.foo.net", "imap2")
imap.authenticate("scram-md5", "bar", "password")
imap.select("inbox")
fetch_thread = Thread.start { imap.fetch(1..-1, "UID") }
search_result = imap.search(["BODY", "hello"])
fetch_result = fetch_thread.value
imap.disconnect

This script invokes the FETCH command and the SEARCH command concurrently.

Errors

An IMAP server can send three different types of responses to indicate failure:

NO

the attempted command could not be successfully completed. For instance, the username/password used for logging in are incorrect; the selected mailbox does not exist; etc.

BAD

the request from the client does not follow the server’s understanding of the IMAP protocol. This includes attempting commands from the wrong client state; for instance, attempting to perform a SEARCH command without having SELECTed a current mailbox. It can also signal an internal server failure (such as a disk crash) has occurred.

BYE

the server is saying goodbye. This can be part of a normal logout sequence, and can be used as part of a login sequence to indicate that the server is (for some reason) unwilling to accept your connection. As a response to any other command, it indicates either that the server is shutting down, or that the server is timing out the client connection due to inactivity.

These three error response are represented by the errors Net::IMAP::NoResponseError, Net::IMAP::BadResponseError, and Net::IMAP::ByeResponseError, all of which are subclasses of Net::IMAP::ResponseError. Essentially, all methods that involve sending a request to the server can generate one of these errors. Only the most pertinent instances have been documented below.

Because the IMAP class uses Sockets for communication, its methods are also susceptible to the various errors that can occur when working with sockets. These are generally represented as Errno errors. For instance, any method that involves sending a request to the server and/or receiving a response from it could raise an Errno::EPIPE error if the network connection unexpectedly goes down. See the socket(7), ip(7), tcp(7), socket(2), connect(2), and associated man pages.

Finally, a Net::IMAP::DataFormatError is thrown if low-level data is found to be in an incorrect format (for instance, when converting between UTF-8 and UTF-16), and Net::IMAP::ResponseParseError is thrown if a server response is non-parseable.

What’s here?

Connection control methods

Server capabilities

Handling server responses

Core IMAP commands

The following commands are defined either by the [IMAP4rev1] base specification, or by one of the following extensions: [IDLE], [NAMESPACE], [UNSELECT], [ENABLE], [MOVE]. These extensions are widely supported by modern IMAP4rev1 servers and have all been integrated into [IMAP4rev2]. NOTE: Net::IMAP doesn’t support IMAP4rev2 yet.

Any state

Not Authenticated state

In addition to the commands for any state, the following commands are valid in the “not authenticated” state:

Authenticated state

In addition to the commands for any state, the following commands are valid in the “authenticated” state:

Selected state

In addition to the commands for any state and the “authenticated” commands, the following commands are valid in the “selected” state:

Logout state

No IMAP commands are valid in the “logout” state. If the socket is still open, Net::IMAP will close it after receiving server confirmation. Exceptions will be raised by IMAP commands that have already started and are waiting for a response, as well as any that are called after logout.

IMAP extension support

RFC9051: IMAP4rev2

Although IMAP4rev2 is not supported yet, Net::IMAP supports several extensions that have been folded into it: ENABLE, IDLE, MOVE, NAMESPACE, SASL-IR, UIDPLUS, UNSELECT, STATUS=SIZE, and the fetch side of BINARY. Commands for these extensions are listed with the Core IMAP commands, above.

The following are folded into IMAP4rev2 but are currently unsupported or incompletely supported by Net::IMAP: RFC4466 extensions, ESEARCH, SEARCHRES, LIST-EXTENDED, LIST-STATUS, LITERAL-, and SPECIAL-USE.

RFC2087: QUOTA

RFC2177: IDLE

Folded into IMAP4rev2 and also included above with Core IMAP commands.

RFC2342: NAMESPACE

Folded into IMAP4rev2 and also included above with Core IMAP commands.

RFC2971: ID

RFC3516: BINARY

The fetch side of BINARY has been folded into IMAP4rev2.

NOTE: The binary extension the append command is not supported yet.

RFC3691: UNSELECT

Folded into IMAP4rev2 and also included above with Core IMAP commands.

RFC4314: ACL

NOTE: DELETEACL, LISTRIGHTS, and MYRIGHTS are not supported yet.

RFC4315: UIDPLUS

Folded into IMAP4rev2 and also included above with Core IMAP commands.

RFC4959: SASL-IR

Folded into IMAP4rev2.

RFC5161: ENABLE

Folded into IMAP4rev2 and also included above with Core IMAP commands.

RFC5256: SORT

RFC5256: THREAD

X-GM-EXT-1

X-GM-EXT-1 is a non-standard Gmail extension. See Google’s documentation.

NOTE: The OBJECTID extension should replace X-GM-MSGID and X-GM-THRID, but Gmail does not support it (as of 2023-11-10).

RFC6851: MOVE

Folded into IMAP4rev2 and also included above with Core IMAP commands.

RFC6855: UTF8=ACCEPT, UTF8=ONLY

RFC7162: CONDSTORE

RFC8438: STATUS=SIZE

RFC8474: OBJECTID

References

[IMAP4rev1]

Crispin, M., “INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1”, RFC 3501, DOI 10.17487/RFC3501, March 2003, <www.rfc-editor.org/info/rfc3501>.

[IMAP-ABNF-EXT]

Melnikov, A. and C. Daboo, “Collected Extensions to IMAP4 ABNF”, RFC 4466, DOI 10.17487/RFC4466, April 2006, <www.rfc-editor.org/info/rfc4466>.

Note: Net::IMAP cannot parse the entire RFC4466 grammar yet.

[IMAP4rev2]

Melnikov, A., Ed., and B. Leiba, Ed., “Internet Message Access Protocol (IMAP) - Version 4rev2”, RFC 9051, DOI 10.17487/RFC9051, August 2021, <www.rfc-editor.org/info/rfc9051>.

Note: Net::IMAP is not fully compatible with IMAP4rev2 yet.

[IMAP-IMPLEMENTATION]

Leiba, B., “IMAP4 Implementation Recommendations”, RFC 2683, DOI 10.17487/RFC2683, September 1999, <www.rfc-editor.org/info/rfc2683>.

[IMAP-MULTIACCESS]

Gahrns, M., “IMAP4 Multi-Accessed Mailbox Practice”, RFC 2180, DOI 10.17487/RFC2180, July 1997, <www.rfc-editor.org/info/rfc2180>.

[UTF7]

Goldsmith, D. and M. Davis, “UTF-7 A Mail-Safe Transformation Format of Unicode”, RFC 2152, DOI 10.17487/RFC2152, May 1997, <www.rfc-editor.org/info/rfc2152>.

Message envelope and body structure

[RFC5322]

Resnick, P., Ed., “Internet Message Format”, RFC 5322, DOI 10.17487/RFC5322, October 2008, <www.rfc-editor.org/info/rfc5322>.

Note: obsoletes RFC-2822 (April 2001) and RFC-822 (August 1982).

[CHARSET]

Freed, N. and J. Postel, “IANA Charset Registration Procedures”, BCP 19, RFC 2978, DOI 10.17487/RFC2978, October 2000, <www.rfc-editor.org/info/rfc2978>.

[DISPOSITION]

Troost, R., Dorner, S., and K. Moore, Ed., “Communicating Presentation Information in Internet Messages: The Content-Disposition Header Field”, RFC 2183, DOI 10.17487/RFC2183, August 1997, <www.rfc-editor.org/info/rfc2183>.

[MIME-IMB]

Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies”, RFC 2045, DOI 10.17487/RFC2045, November 1996, <www.rfc-editor.org/info/rfc2045>.

[MIME-IMT]

Freed, N. and N. Borenstein, “Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types”, RFC 2046, DOI 10.17487/RFC2046, November 1996, <www.rfc-editor.org/info/rfc2046>.

[MIME-HDRS]

Moore, K., “MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text”, RFC 2047, DOI 10.17487/RFC2047, November 1996, <www.rfc-editor.org/info/rfc2047>.

[RFC2231]

Freed, N. and K. Moore, “MIME Parameter Value and Encoded Word Extensions: Character Sets, Languages, and Continuations”, RFC 2231, DOI 10.17487/RFC2231, November 1997, <www.rfc-editor.org/info/rfc2231>.

[I18n-HDRS]

Yang, A., Steele, S., and N. Freed, “Internationalized Email Headers”, RFC 6532, DOI 10.17487/RFC6532, February 2012, <www.rfc-editor.org/info/rfc6532>.

[LANGUAGE-TAGS]

Alvestrand, H., “Content Language Headers”, RFC 3282, DOI 10.17487/RFC3282, May 2002, <www.rfc-editor.org/info/rfc3282>.

[LOCATION]

Palme, J., Hopmann, A., and N. Shelness, “MIME Encapsulation of Aggregate Documents, such as HTML (MHTML)”, RFC 2557, DOI 10.17487/RFC2557, March 1999, <www.rfc-editor.org/info/rfc2557>.

[MD5]

Myers, J. and M. Rose, “The Content-MD5 Header Field”, RFC 1864, DOI 10.17487/RFC1864, October 1995, <www.rfc-editor.org/info/rfc1864>.

[RFC3503]

Melnikov, A., “Message Disposition Notification (MDN) profile for Internet Message Access Protocol (IMAP)”, RFC 3503, DOI 10.17487/RFC3503, March 2003, <www.rfc-editor.org/info/rfc3503>.

IMAP Extensions

[QUOTA]

Melnikov, A., “IMAP QUOTA Extension”, RFC 9208, DOI 10.17487/RFC9208, March 2022, <www.rfc-editor.org/info/rfc9208>.

Note: obsoletes RFC-2087 (January 1997). Net::IMAP does not fully support the RFC9208 updates yet.

[IDLE]

Leiba, B., “IMAP4 IDLE command”, RFC 2177, DOI 10.17487/RFC2177, June 1997, <www.rfc-editor.org/info/rfc2177>.

[NAMESPACE]

Gahrns, M. and C. Newman, “IMAP4 Namespace”, RFC 2342, DOI 10.17487/RFC2342, May 1998, <www.rfc-editor.org/info/rfc2342>.

[ID]

Showalter, T., “IMAP4 ID extension”, RFC 2971, DOI 10.17487/RFC2971, October 2000, <www.rfc-editor.org/info/rfc2971>.

[BINARY]

Nerenberg, L., “IMAP4 Binary Content Extension”, RFC 3516, DOI 10.17487/RFC3516, April 2003, <www.rfc-editor.org/info/rfc3516>.

[ACL]

Melnikov, A., “IMAP4 Access Control List (ACL) Extension”, RFC 4314, DOI 10.17487/RFC4314, December 2005, <www.rfc-editor.org/info/rfc4314>.

[UIDPLUS]

Crispin, M., “Internet Message Access Protocol (IMAP) - UIDPLUS extension”, RFC 4315, DOI 10.17487/RFC4315, December 2005, <www.rfc-editor.org/info/rfc4315>.

[SORT]

Crispin, M. and K. Murchison, “Internet Message Access Protocol - SORT and THREAD Extensions”, RFC 5256, DOI 10.17487/RFC5256, June 2008, <www.rfc-editor.org/info/rfc5256>.

[THREAD]

Crispin, M. and K. Murchison, “Internet Message Access Protocol - SORT and THREAD Extensions”, RFC 5256, DOI 10.17487/RFC5256, June 2008, <www.rfc-editor.org/info/rfc5256>.

[RFC5530]

Gulbrandsen, A., “IMAP Response Codes”, RFC 5530, DOI 10.17487/RFC5530, May 2009, <www.rfc-editor.org/info/rfc5530>.

[MOVE]

Gulbrandsen, A. and N. Freed, Ed., “Internet Message Access Protocol (IMAP) - MOVE Extension”, RFC 6851, DOI 10.17487/RFC6851, January 2013, <www.rfc-editor.org/info/rfc6851>.

[UTF8=ACCEPT]
[UTF8=ONLY]

Resnick, P., Ed., Newman, C., Ed., and S. Shen, Ed., “IMAP Support for UTF-8”, RFC 6855, DOI 10.17487/RFC6855, March 2013, <www.rfc-editor.org/info/rfc6855>.

[CONDSTORE]
[QRESYNC]

Melnikov, A. and D. Cridland, “IMAP Extensions: Quick Flag Changes Resynchronization (CONDSTORE) and Quick Mailbox Resynchronization (QRESYNC)”, RFC 7162, DOI 10.17487/RFC7162, May 2014, <www.rfc-editor.org/info/rfc7162>.

[OBJECTID]

Gondwana, B., Ed., “IMAP Extension for Object Identifiers”, RFC 8474, DOI 10.17487/RFC8474, September 2018, <www.rfc-editor.org/info/rfc8474>.

IANA registries

For currently unsupported features:

Constants

ENABLE_ALIASES

Aliases for supported capabilities, to be used with the enable command.

STRFDATE

strftime/strptime format for an IMAP4 date, excluding optional dquotes. Use via the encode_date and decode_date methods.

date            = date-text / DQUOTE date-text DQUOTE
date-text       = date-day "-" date-month "-" date-year

date-day        = 1*2DIGIT
                    ; Day of month
date-month      = "Jan" / "Feb" / "Mar" / "Apr" / "May" / "Jun" /
                  "Jul" / "Aug" / "Sep" / "Oct" / "Nov" / "Dec"
date-year       = 4DIGIT
STRFTIME

strftime/strptime format for an IMAP4 date-time, including dquotes. See the encode_datetime and decode_datetime methods.

date-time       = DQUOTE date-day-fixed "-" date-month "-" date-year
                  SP time SP zone DQUOTE

date-day-fixed  = (SP DIGIT) / 2DIGIT
                    ; Fixed-format version of date-day
date-month      = "Jan" / "Feb" / "Mar" / "Apr" / "May" / "Jun" /
                  "Jul" / "Aug" / "Sep" / "Oct" / "Nov" / "Dec"
date-year       = 4DIGIT
time            = 2DIGIT ":" 2DIGIT ":" 2DIGIT
                    ; Hours minutes seconds
zone            = ("+" / "-") 4DIGIT
                    ; Signed four-digit value of hhmm representing
                    ; hours and minutes east of Greenwich (that is,
                    ; the amount that the given time differs from
                    ; Universal Time).  Subtracting the timezone
                    ; from the given time will give the UT form.
                    ; The Universal Time zone is "+0000".

Note that Time.strptime "%d" flexibly parses either space or zero padding. However, the DQUOTEs are not optional.

VERSION

Attributes

config[R]

The client configuration. See Net::IMAP::Config.

By default, the client’s local configuration inherits from the global Net::IMAP.config.

greeting[R]

Returns the initial greeting the server, an UntaggedResponse.

host[R]

The hostname this client connected to

port[R]

The port this client connected to

ssl_ctx[R]

Returns the SSLContext used by the SSLSocket when TLS is attempted, even when the TLS handshake is unsuccessful. The context object will be frozen.

Returns nil for a plaintext connection.

ssl_ctx_params[R]

Returns the parameters that were sent to ssl_ctx set_params when the connection tries to use TLS (even when unsuccessful).

Returns false for a plaintext connection.

Public Class Methods

config click to toggle source

Returns the global Config object

# File lib/net/imap.rb, line 741
def self.config; Config.global end
debug click to toggle source

Returns the global debug mode.

# File lib/net/imap.rb, line 744
def self.debug; config.debug end
debug=(val) click to toggle source

Sets the global debug mode.

# File lib/net/imap.rb, line 747
def self.debug=(val)
  config.debug = val
end
decode_date(string) → Date click to toggle source

Decodes string as an IMAP formatted “date”.

Double quotes are optional. Day of month may be padded with zero or space. See STRFDATE.

# File lib/net/imap/data_encoding.rb, line 90
def self.decode_date(string)
  string = string.delete_prefix('"').delete_suffix('"')
  Date.strptime(string, STRFDATE)
end
Also aliased as: parse_date
decode_datetime(string) → DateTime click to toggle source

Decodes string as an IMAP4 formatted “date-time”.

NOTE: Although double-quotes are not optional in the IMAP grammar, Net::IMAP currently parses “date-time” values as “quoted” strings and this removes the quotation marks. To be useful for strings which have already been parsed as a quoted string, this method makes double-quotes optional.

See STRFTIME.

# File lib/net/imap/data_encoding.rb, line 112
def self.decode_datetime(string)
  unless string.start_with?(?") && string.end_with?(?")
    string = '"%s"' % [string]
  end
  DateTime.strptime(string, STRFTIME)
end
Also aliased as: parse_datetime
decode_time(string) → Time click to toggle source

Decodes string as an IMAP4 formatted “date-time”.

Same as decode_datetime, but returning a Time instead.

# File lib/net/imap/data_encoding.rb, line 124
def self.decode_time(string)
  unless string.start_with?(?") && string.end_with?(?")
    string = '"%s"' % [string]
  end
  Time.strptime(string, STRFTIME)
end
Also aliased as: parse_time
decode_utf7(s) click to toggle source

Decode a string from modified UTF-7 format to UTF-8.

UTF-7 is a 7-bit encoding of Unicode [UTF7]. IMAP uses a slightly modified version of this to encode mailbox names containing non-ASCII characters; see [IMAP] section 5.1.3.

Net::IMAP does not automatically encode and decode mailbox names to and from UTF-7.

# File lib/net/imap/data_encoding.rb, line 57
def self.decode_utf7(s)
  return s.gsub(/&([A-Za-z0-9+,]+)?-/n) {
    if base64 = $1
      (base64.tr(",", "/") + "===").unpack1("m").encode(Encoding::UTF_8, Encoding::UTF_16BE)
    else
      "&"
    end
  }
end
default_imap_port
Alias for: default_port
default_imaps_port
Alias for: default_tls_port
default_port click to toggle source

The default port for IMAP connections, port 143

# File lib/net/imap.rb, line 752
def self.default_port
  return PORT
end
Also aliased as: default_imap_port
default_ssl_port
Alias for: default_tls_port
default_tls_port click to toggle source

The default port for IMAPS connections, port 993

# File lib/net/imap.rb, line 757
def self.default_tls_port
  return SSL_PORT
end
encode_date(date) click to toggle source

Formats time as an IMAP4 date.

# File lib/net/imap/data_encoding.rb, line 80
def self.encode_date(date)
  date.to_date.strftime STRFDATE
end
Also aliased as: format_date
encode_datetime(time) → string click to toggle source

Formats time as an IMAP4 date-time.

# File lib/net/imap/data_encoding.rb, line 98
def self.encode_datetime(time)
  time.to_datetime.strftime STRFTIME
end
Also aliased as: encode_time
encode_time
Also aliased as: format_time
Alias for: encode_datetime
encode_utf7(s) click to toggle source

Encode a string from UTF-8 format to modified UTF-7.

# File lib/net/imap/data_encoding.rb, line 68
def self.encode_utf7(s)
  return s.gsub(/(&)|[^\x20-\x7e]+/) {
    if $1
      "&-"
    else
      base64 = [$&.encode(Encoding::UTF_16BE)].pack("m0")
      "&" + base64.delete("=").tr("/", ",") + "-"
    end
  }.force_encoding("ASCII-8BIT")
end
format_date(date)
Alias for: encode_date
format_datetime(time) click to toggle source
DEPRECATED

The original version returned incorrectly formatted strings. Strings returned by encode_datetime or format_time use the correct IMAP4rev1 syntax for “date-time”.

This invalid format has been temporarily retained for backward compatibility. A future release will change this method to return the correct format.

# File lib/net/imap/data_encoding.rb, line 149
def self.format_datetime(time)
  warn("#{self}.format_datetime incorrectly formats IMAP date-time. " \
       "Convert to #{self}.encode_datetime or #{self}.format_time instead.",
       uplevel: 1, category: :deprecated)
  time.strftime("%d-%b-%Y %H:%M %z")
end
format_time(time)
Alias for: encode_time
new(host, port: nil, ssl: nil, config: Config.global, **config_options) click to toggle source

Creates a new Net::IMAP object and connects it to the specified host.

Options

Accepts the following options:

port

Port number. Defaults to 993 when ssl is truthy, and 143 otherwise.

ssl

If true, the connection will use TLS with the default params set by OpenSSL::SSL::SSLContext#set_params. If ssl is a hash, it’s passed to OpenSSL::SSL::SSLContext#set_params; the keys are names of attribute assignment methods on SSLContext. For example:

ca_file

The path to a file containing a PEM-format CA certificate.

ca_path

The path to a directory containing CA certificates in PEM format.

min_version

Sets the lower bound on the supported SSL/TLS protocol version. Set to an OpenSSL constant such as OpenSSL::SSL::TLS1_2_VERSION,

verify_mode

SSL session verification mode. Valid modes include OpenSSL::SSL::VERIFY_PEER and OpenSSL::SSL::VERIFY_NONE.

See OpenSSL::SSL::SSLContext for other valid SSL context params.

See DeprecatedClientOptions.new for deprecated SSL arguments.

config

A Net::IMAP::Config object to use as the basis for config. By default, the global Net::IMAP.config is used.

NOTE: config does not set config directly—it sets the parent config for inheritance. Every client creates its own unique config.

All other keyword arguments are forwarded to Net::IMAP::Config.new, to initialize the client’s config. For example:

open_timeout

Seconds to wait until a connection is opened

idle_response_timeout

Seconds to wait until an IDLE response is received

See Net::IMAP::Config for other valid options.

Examples

Connect to cleartext port 143 at mail.example.com and receive the server greeting:

imap = Net::IMAP.new('mail.example.com', ssl: false) # => #<Net::IMAP:0x00007f79b0872bd0>
imap.port          => 143
imap.tls_verified? => false
imap.greeting      => name: ("OK" | "PREAUTH") => status
status # => "OK"
# The client is connected in the "Not Authenticated" state.

Connect with TLS to port 993

imap = Net::IMAP.new('mail.example.com', ssl: true) # => #<Net::IMAP:0x00007f79b0872bd0>
imap.port          => 993
imap.tls_verified? => true
imap.greeting      => name: (/OK/i | /PREAUTH/i) => status
case status
in /OK/i
  # The client is connected in the "Not Authenticated" state.
  imap.authenticate("PLAIN", "joe_user", "joes_password")
in /PREAUTH/i
  # The client is connected in the "Authenticated" state.
end

Connect with prior authentication, for example using an SSL certificate:

ssl_ctx_params = {
  cert: OpenSSL::X509::Certificate.new(File.read("client.crt")),
  key:  OpenSSL::PKey::EC.new(File.read('client.key')),
  extra_chain_cert: [
    OpenSSL::X509::Certificate.new(File.read("intermediate.crt")),
  ],
}
imap = Net::IMAP.new('mail.example.com', ssl: ssl_ctx_params)
imap.port          => 993
imap.tls_verified? => true
imap.greeting      => name: "PREAUTH"
# The client is connected in the "Authenticated" state.

Exceptions

The most common errors are:

Errno::ECONNREFUSED

Connection refused by host or an intervening firewall.

Errno::ETIMEDOUT

Connection timed out (possibly due to packets being dropped by an intervening firewall).

Errno::ENETUNREACH

There is no route to that network.

SocketError

Hostname not known or other socket error.

Net::IMAP::ByeResponseError

Connected to the host successfully, but it immediately said goodbye.

Calls superclass method
# File lib/net/imap.rb, line 909
def initialize(host, port: nil, ssl:  nil,
               config: Config.global, **config_options)
  super()
  # Config options
  @host = host
  @config = Config.new(config, **config_options)
  @port = port || (ssl ? SSL_PORT : PORT)
  @ssl_ctx_params, @ssl_ctx = build_ssl_ctx(ssl)

  # Basic Client State
  @utf8_strings = false
  @debug_output_bol = true
  @exception = nil
  @greeting = nil
  @capabilities = nil

  # Client Protocol Receiver
  @parser = ResponseParser.new(config: @config)
  @responses = Hash.new {|h, k| h[k] = [] }
  @response_handlers = []
  @receiver_thread = nil
  @receiver_thread_exception = nil
  @receiver_thread_terminating = false

  # Client Protocol Sender (including state for currently running commands)
  @tag_prefix = "RUBY"
  @tagno = 0
  @tagged_responses = {}
  @tagged_response_arrival = new_cond
  @continued_command_tag = nil
  @continuation_request_arrival = new_cond
  @continuation_request_exception = nil
  @idle_done_cond = nil
  @logout_command_tag = nil

  # Connection
  @tls_verified = false
  @sock = tcp_socket(@host, @port)
  start_tls_session if ssl_ctx
  start_imap_connection
end
parse_date
Alias for: decode_date
parse_datetime
Alias for: decode_datetime
parse_time
Alias for: decode_time
saslprep(string, **opts) click to toggle source

Delegates to Net::IMAP::StringPrep::SASLprep#saslprep.

# File lib/net/imap.rb, line 3268
def self.saslprep(string, **opts)
  Net::IMAP::StringPrep::SASLprep.saslprep(string, **opts)
end

Public Instance Methods

add_response_handler(handler = nil, &block) click to toggle source

Adds a response handler. For example, to detect when the server sends a new EXISTS response (which normally indicates new messages being added to the mailbox), add the following handler after selecting the mailbox:

imap.add_response_handler { |resp|
  if resp.kind_of?(Net::IMAP::UntaggedResponse) and resp.name == "EXISTS"
    puts "Mailbox now has #{resp.data} messages"
  end
}

Related: remove_response_handler, response_handlers

# File lib/net/imap.rb, line 2868
def add_response_handler(handler = nil, &block)
  raise ArgumentError, "two Procs are passed" if handler && block
  synchronize do
    @response_handlers.push(block || handler)
  end
end
append(mailbox, message, flags = nil, date_time = nil) click to toggle source

Sends an APPEND command [IMAP4rev1 §6.3.11] to append the message to the end of the mailbox. The optional flags argument is an array of flags initially passed to the new message. The optional date_time argument specifies the creation time to assign to the new message; it defaults to the current time.

For example:

imap.append("inbox", <<EOF.gsub(/\n/, "\r\n"), [:Seen], Time.now)
Subject: hello
From: shugo@ruby-lang.org
To: shugo@ruby-lang.org

hello world
EOF

A Net::IMAP::NoResponseError is raised if the mailbox does not exist (it is not created automatically), or if the flags, date_time, or message arguments contain errors.

Capabilities

If UIDPLUS [RFC4315] is supported and the destination supports persistent UIDs, the server’s response should include an APPENDUID response code with UIDPlusData. This will report the UIDVALIDITY of the destination mailbox and the assigned UID of the appended message.

# File lib/net/imap.rb, line 1842
def append(mailbox, message, flags = nil, date_time = nil)
  args = []
  if flags
    args.push(flags)
  end
  args.push(date_time) if date_time
  args.push(Literal.new(message))
  send_command("APPEND", mailbox, *args)
end
auth_capable?(mechanism) click to toggle source

Returns whether the server supports a given SASL mechanism for use with the authenticate command. The mechanism is supported when capabilities includes "AUTH=#{mechanism.to_s.upcase}". When available, cached capabilities are used without sending a new capability command to the server.

imap.capable?      "AUTH=PLAIN"  # => true
imap.auth_capable? "PLAIN"       # => true
imap.auth_capable? "blurdybloop" # => false

Related: authenticate, auth_mechanisms, capable?, capabilities

# File lib/net/imap.rb, line 1053
def auth_capable?(mechanism)
  capable? "AUTH=#{mechanism}"
end
auth_mechanisms click to toggle source

Returns the authenticate mechanisms that the server claims to support. These are derived from the capabilities with an AUTH= prefix.

This may be different when the connection is cleartext or using TLS. Most servers will drop all AUTH= mechanisms from capabilities after the connection has authenticated.

imap = Net::IMAP.new(hostname, ssl: false)
imap.capabilities    # => ["IMAP4REV1", "LOGINDISABLED"]
imap.auth_mechanisms # => []

imap.starttls
imap.capabilities    # => ["IMAP4REV1", "AUTH=PLAIN", "AUTH=XOAUTH2",
                     #     "AUTH=OAUTHBEARER"]
imap.auth_mechanisms # => ["PLAIN", "XOAUTH2", "OAUTHBEARER"]

imap.authenticate("XOAUTH2", username, oauth2_access_token)
imap.auth_mechanisms # => []

Related: authenticate, auth_capable?, capabilities

# File lib/net/imap.rb, line 1036
def auth_mechanisms
  capabilities
    .grep(/\AAUTH=/i)
    .map { _1.delete_prefix("AUTH=") }
end
authenticate(mechanism, *, sasl_ir: config.sasl_ir, registry: Net::IMAP::SASL.authenticators, **, &) → ok_resp click to toggle source

Sends an AUTHENTICATE command [IMAP4rev1 §6.2.2] to authenticate the client. If successful, the connection enters the “authenticated” state.

mechanism is the name of the SASL authentication mechanism to be used.

sasl_ir allows or disallows sending an “initial response” (see the SASL-IR capability, below). Defaults to the config value for sasl_ir, which defaults to true.

The registry kwarg can be used to select the mechanism implementation from a custom registry. See SASL.authenticator and SASL::Authenticators.

All other arguments are forwarded to the registered SASL authenticator for the requested mechanism. The documentation for each individual mechanism must be consulted for its specific parameters.

Related: login, starttls, auth_capable?, auth_mechanisms

Mechanisms

Each mechanism has different properties and requirements. Please consult the documentation for the specific mechanisms you are using:

ANONYMOUS

See AnonymousAuthenticator.

Allows the user to gain access to public services or resources without authenticating or disclosing an identity.

EXTERNAL

See ExternalAuthenticator.

Authenticates using already established credentials, such as a TLS certificate or IPsec.

OAUTHBEARER

See OAuthBearerAuthenticator.

Login using an OAuth2 Bearer token. This is the standard mechanism for using OAuth2 with SASL, but it is not yet deployed as widely as XOAUTH2.

PLAIN

See PlainAuthenticator.

Login using clear-text username and password.

SCRAM-SHA-1
SCRAM-SHA-256

See ScramAuthenticator.

Login by username and password. The password is not sent to the server but is used in a salted challenge/response exchange. SCRAM-SHA-1 and SCRAM-SHA-256 are directly supported by Net::IMAP::SASL. New authenticators can easily be added for any other SCRAM-* mechanism if the digest algorithm is supported by OpenSSL::Digest.

XOAUTH2

See XOAuth2Authenticator.

Login using a username and an OAuth2 access token. Non-standard and obsoleted by OAUTHBEARER, but widely supported.

See the SASL mechanism registry for a list of all SASL mechanisms and their specifications. To register new authenticators, see Authenticators.

Deprecated mechanisms

Obsolete mechanisms should be avoided, but are still available for backwards compatibility. See Deprecated mechanisms at Net::IMAP::SASL. Using a deprecated mechanism will print a warning.

Capabilities

"AUTH=#{mechanism}" capabilities indicate server support for mechanisms. Use auth_capable? or auth_mechanisms to check for support before using a particular mechanism.

if imap.auth_capable? "XOAUTH2"
  imap.authenticate "XOAUTH2", username, oauth2_access_token
elsif imap.auth_capable? "PLAIN"
  imap.authenticate "PLAIN", username, password
elsif !imap.capability? "LOGINDISABLED"
  imap.login username, password
else
  raise "No acceptable authentication mechanism is available"
end

Although servers should list all supported SASL mechanisms, they may allow authentication with an unlisted mechanism.

If [SASL-IR] is supported and the appropriate "AUTH=#{mechanism}" capability is present, an “initial response” may be sent as an argument to the AUTHENTICATE command, saving a round-trip. The SASL exchange allows for server challenges and client responses, but many mechanisms expect the client to “respond” first. The initial response will only be sent for “client-first” mechanisms.

Server capabilities may change after starttls, login, and authenticate. Previously cached capabilities will be cleared when this method completes. If the TaggedResponse to authenticate includes updated capabilities, they will be cached.

# File lib/net/imap.rb, line 1336
def authenticate(*args, sasl_ir: config.sasl_ir, **props, &callback)
  sasl_adapter.authenticate(*args, sasl_ir: sasl_ir, **props, &callback)
    .tap { @capabilities = capabilities_from_resp_code _1 }
end
capabilities click to toggle source

Returns the server capabilities. When available, cached capabilities are used without sending a new capability command to the server.

To ensure a case-insensitive comparison, capable? can be used instead.

NOTE: Most Net::IMAP methods do not currently modify their behaviour according to the server’s advertised #capabilities.

See Capabilities at Net::IMAP for more about IMAP capabilities.

Related: capable?, auth_capable?, auth_mechanisms, capability, enable

# File lib/net/imap.rb, line 1012
def capabilities
  @capabilities || capability
end
capabilities_cached? click to toggle source

Returns whether capabilities have been cached. When true, capable? and capabilities don’t require sending a capability command to the server.

See Capabilities at Net::IMAP for more about IMAP capabilities.

Related: capable?, capability, clear_cached_capabilities

# File lib/net/imap.rb, line 1063
def capabilities_cached?
  !!@capabilities
end
capability click to toggle source

Sends a CAPABILITY command [IMAP4rev1 §6.1.1] and returns an array of capabilities that are supported by the server. The result is stored for use by capable? and capabilities.

NOTE: Most Net::IMAP methods do not currently modify their behaviour according to the server’s advertised #capabilities.

Net::IMAP automatically stores and discards capability data according to the requirements and recommendations in IMAP4rev2 §6.1.1, §6.2, and §7.1. Use capable?, auth_capable?, or capabilities to this cache and avoid sending the capability command unnecessarily.

See Capabilities at Net::IMAP for more about IMAP capabilities.

Related: capable?, auth_capable?, capability, enable

# File lib/net/imap.rb, line 1101
def capability
  synchronize do
    send_command("CAPABILITY")
    @capabilities = clear_responses("CAPABILITY").last.freeze
  end
end
capability?(capability)
Alias for: capable?
capable?(capability) click to toggle source

Returns whether the server supports a given capability. When available, cached capabilities are used without sending a new capability command to the server.

NOTE: Most Net::IMAP methods do not currently modify their behaviour according to the server’s advertised #capabilities.

See Capabilities at Net::IMAP for more about IMAP capabilities.

Related: auth_capable?, capabilities, capability, enable

# File lib/net/imap.rb, line 998
def capable?(capability) capabilities.include? capability.to_s.upcase end
Also aliased as: capability?
check click to toggle source

Sends a CHECK command [IMAP4rev1 §6.4.1] to request a checkpoint of the currently selected mailbox. This performs implementation-specific housekeeping; for instance, reconciling the mailbox’s in-memory and on-disk state.

Related: idle, noop

# File lib/net/imap.rb, line 1858
def check
  send_command("CHECK")
end
clear_cached_capabilities click to toggle source

Clears capabilities that have been remembered by the Net::IMAP client. This forces a capability command to be sent the next time a capabilities query method is called.

Net::IMAP automatically discards its cached capabilities when they can change. Explicitly calling this should be unnecessary for well-behaved servers.

Related: capable?, capability, capabilities_cached?

# File lib/net/imap.rb, line 1076
def clear_cached_capabilities
  synchronize do
    clear_responses("CAPABILITY")
    @capabilities = nil
  end
end
clear_responses → hash click to toggle source
clear_responses(type) → array

Clears and returns the unhandled responses hash or the unhandled responses array for a single response type.

Clearing responses is synchronized with other threads. The lock is released before returning.

Related: extract_responses, responses, response_handlers

# File lib/net/imap.rb, line 2801
def clear_responses(type = nil)
  synchronize {
    if type
      @responses.delete(type) || []
    else
      @responses.dup.transform_values(&:freeze)
        .tap { _1.default = [].freeze }
        .tap { @responses.clear }
    end
  }
    .freeze
end
close click to toggle source

Sends a CLOSE command [IMAP4rev1 §6.4.2] to close the currently selected mailbox. The CLOSE command permanently removes from the mailbox all messages that have the \Deleted flag set.

Related: unselect

# File lib/net/imap.rb, line 1868
def close
  send_command("CLOSE")
end
copy(set, mailbox) click to toggle source

Sends a COPY command [IMAP4rev1 §6.4.7] to copy the specified message(s) to the end of the specified destination mailbox. The set parameter is a number, an array of numbers, or a Range object. The number is a message sequence number.

Related: uid_copy

Capabilities

If UIDPLUS [RFC4315] is supported, the server’s response should include a COPYUID response code with UIDPlusData. This will report the UIDVALIDITY of the destination mailbox, the UID set of the source messages, and the assigned UID set of the moved messages.

# File lib/net/imap.rb, line 2365
def copy(set, mailbox)
  copy_internal("COPY", set, mailbox)
end
create(mailbox) click to toggle source

Sends a CREATE command [IMAP4rev1 §6.3.3] to create a new mailbox.

A Net::IMAP::NoResponseError is raised if a mailbox with that name cannot be created.

Related: rename, delete

# File lib/net/imap.rb, line 1442
def create(mailbox)
  send_command("CREATE", mailbox)
end
delete(mailbox) click to toggle source

Sends a DELETE command [IMAP4rev1 §6.3.4] to remove the mailbox.

A Net::IMAP::NoResponseError is raised if a mailbox with that name cannot be deleted, either because it does not exist or because the client does not have permission to delete it.

Related: create, rename

# File lib/net/imap.rb, line 1454
def delete(mailbox)
  send_command("DELETE", mailbox)
end
disconnect click to toggle source

Disconnects from the server.

Related: logout, logout!

# File lib/net/imap.rb, line 959
def disconnect
  return if disconnected?
  begin
    begin
      # try to call SSL::SSLSocket#io.
      @sock.io.shutdown
    rescue NoMethodError
      # @sock is not an SSL::SSLSocket.
      @sock.shutdown
    end
  rescue Errno::ENOTCONN
    # ignore `Errno::ENOTCONN: Socket is not connected' on some platforms.
  rescue Exception => e
    @receiver_thread.raise(e)
  end
  @receiver_thread.join
  synchronize do
    @sock.close
  end
  raise e if e
end
disconnected? click to toggle source

Returns true if disconnected from the server.

Related: logout, disconnect

# File lib/net/imap.rb, line 984
def disconnected?
  return @sock.closed?
end
enable(*capabilities) click to toggle source

Sends an ENABLE command [RFC5161 §3.2] [IMAP4rev2 §6.3.1] to enable the specified server capabilities. Each capability may be an array, string, or symbol. Returns a list of the capabilities that were enabled.

The ENABLE command is only valid in the authenticated state, before any mailbox is selected.

Related: capable?, capabilities, capability

Capabilities

The server’s capabilities must include ENABLE [RFC5161] or IMAP4REV2 [RFC9051].

Additionally, the server capabilities must include a capability matching each enabled extension (usually the same name as the enabled extension). The following capabilities may be enabled:

CONDSTORE [RFC7162]

Updates various commands to return CONDSTORE extension responses. It is not necessary to explicitly enable CONDSTORE—using any of the command parameters defined by the extension will implicitly enable it. See [RFC7162 §3.1].

:utf8 — an alias for "UTF8=ACCEPT"

In a future release, enable(:utf8) will enable either "UTF8=ACCEPT" or "IMAP4rev2", depending on server capabilities.

"UTF8=ACCEPT" [RFC6855]

The server’s capabilities must include UTF8=ACCEPT or UTF8=ONLY.

This allows the server to send strings encoded as UTF-8 which might otherwise need to use a 7-bit encoding, such as modified UTF-7 for mailbox names, or RFC2047 encoded-words for message headers.

Note: A future update may set string encodings slightly differently, e.g: “US-ASCII” when UTF-8 is not enabled, and “UTF-8” when it is. Currently, the encoding of strings sent as “quoted” or “text” will always be “UTF-8”, even when only ASCII characters are used (e.g. “Subject: Agenda”) And currently, string “literals” sent by the server will always have an “ASCII-8BIT” (binary) encoding, even if they generally contain UTF-8 data, if they are text at all.

"UTF8=ONLY" [RFC6855]

A server that reports the UTF8=ONLY capability requires that the client enable("UTF8=ACCEPT") before any mailboxes may be selected. For convenience, enable("UTF8=ONLY") is aliased to enable("UTF8=ACCEPT").

Unsupported capabilities

Note: Some extensions that use ENABLE permit the server to send syntax that Net::IMAP cannot parse, which may raise an exception and disconnect. Some extensions may work, but the support may be incomplete, untested, or experimental.

Until a capability is documented here as supported, enabling it may result in undocumented behavior and a future release may update with incompatible behavior without warning or deprecation.

Caution is advised.

# File lib/net/imap.rb, line 2576
def enable(*capabilities)
  capabilities = capabilities
    .flatten
    .map {|e| ENABLE_ALIASES[e] || e }
    .uniq
    .join(' ')
  synchronize do
    send_command("ENABLE #{capabilities}")
    result = clear_responses("ENABLED").last || []
    @utf8_strings ||= result.include? "UTF8=ACCEPT"
    @utf8_strings ||= result.include? "IMAP4REV2"
    result
  end
end
examine(mailbox, condstore: false) click to toggle source

Sends a EXAMINE command [IMAP4rev1 §6.3.2] to select a mailbox so that messages in the mailbox can be accessed. Behaves the same as select, except that the selected mailbox is identified as read-only.

A Net::IMAP::NoResponseError is raised if the mailbox does not exist or is for some reason non-examinable.

Related: select

# File lib/net/imap.rb, line 1426
def examine(mailbox, condstore: false)
  args = ["EXAMINE", mailbox]
  args << ["CONDSTORE"] if condstore
  synchronize do
    @responses.clear
    send_command(*args)
  end
end
expunge click to toggle source

Sends an EXPUNGE command [IMAP4rev1 §6.4.3] Sends a EXPUNGE command to permanently remove from the currently selected mailbox all messages that have the Deleted flag set.

Related: uid_expunge

# File lib/net/imap.rb, line 1893
def expunge
  synchronize do
    send_command("EXPUNGE")
    clear_responses("EXPUNGE")
  end
end
extract_responses(type) {|response| ... } → array click to toggle source

Yields all of the unhandled responses for a single response type. Removes and returns the responses for which the block returns a true value.

Extracting responses is synchronized with other threads. The lock is released before returning.

Related: responses, clear_responses

# File lib/net/imap.rb, line 2825
def extract_responses(type)
  type = String.try_convert(type) or
    raise ArgumentError, "type must be a string"
  raise ArgumentError, "must provide a block" unless block_given?
  extracted = []
  responses(type) do |all|
    all.reject! do |response|
      extracted << response if yield response
    end
  end
  extracted
end
fetch(set, attr, changedsince: nil) → array of FetchData click to toggle source

Sends a FETCH command [IMAP4rev1 §6.4.5] to retrieve data associated with a message in the mailbox.

The set parameter is a number or a range between two numbers, or an array of those. The number is a message sequence number, where -1 represents a ‘*’ for use in range notation like 100..-1 being interpreted as ‘100:*’. Beware that the exclude_end? property of a Range object is ignored, and the contents of a range are independent of the order of the range endpoints as per the protocol specification, so 1…5, 5..1 and 5…1 are all equivalent to 1..5.

attr is a list of attributes to fetch; see the documentation for FetchData for a list of valid attributes.

changedsince is an optional integer mod-sequence. It limits results to messages with a mod-sequence greater than changedsince.

The return value is an array of FetchData.

Related: uid_search, FetchData

For example:
p imap.fetch(6..8, "UID")
#=> [#<Net::IMAP::FetchData seqno=6, attr={"UID"=>98}>, \\
     #<Net::IMAP::FetchData seqno=7, attr={"UID"=>99}>, \\
     #<Net::IMAP::FetchData seqno=8, attr={"UID"=>100}>]
p imap.fetch(6, "BODY[HEADER.FIELDS (SUBJECT)]")
#=> [#<Net::IMAP::FetchData seqno=6, attr={"BODY[HEADER.FIELDS (SUBJECT)]"=>"Subject: test\r\n\r\n"}>]
data = imap.uid_fetch(98, ["RFC822.SIZE", "INTERNALDATE"])[0]
p data.seqno
#=> 6
p data.attr["RFC822.SIZE"]
#=> 611
p data.attr["INTERNALDATE"]
#=> "12-Oct-2000 22:40:59 +0900"
p data.attr["UID"]
#=> 98
Capabilities

Many extensions define new message attr names. See FetchData for a list of supported extension fields.

The server’s capabilities must include CONDSTORE [RFC7162] in order to use the changedsince argument. Using changedsince implicitly enables the CONDSTORE extension.

# File lib/net/imap.rb, line 2260
def fetch(set, attr, mod = nil, changedsince: nil)
  fetch_internal("FETCH", set, attr, mod, changedsince: changedsince)
end
getacl(mailbox) click to toggle source

Sends a GETACL command [RFC4314 §3.3] along with a specified mailbox. If this mailbox exists, an array containing objects of MailboxACLItem will be returned.

Related: setacl, MailboxACLItem

Capabilities

The server’s capabilities must include ACL [RFC4314].

# File lib/net/imap.rb, line 1722
def getacl(mailbox)
  synchronize do
    send_command("GETACL", mailbox)
    clear_responses("ACL").last
  end
end
getquota(mailbox) click to toggle source

Sends a GETQUOTA command [RFC2087 §4.2] along with specified mailbox. If this mailbox exists, then an array containing a MailboxQuota object is returned. This command is generally only available to server admin.

Related: getquotaroot, setquota, MailboxQuota

Capabilities

The server’s capabilities must include QUOTA [RFC2087].

# File lib/net/imap.rb, line 1666
def getquota(mailbox)
  synchronize do
    send_command("GETQUOTA", mailbox)
    clear_responses("QUOTA")
  end
end
getquotaroot(mailbox) click to toggle source

Sends a GETQUOTAROOT command [RFC2087 §4.3] along with the specified mailbox. This command is generally available to both admin and user. If this mailbox exists, it returns an array containing objects of type MailboxQuotaRoot and MailboxQuota.

Related: getquota, setquota, MailboxQuotaRoot, MailboxQuota

Capabilities

The server’s capabilities must include QUOTA [RFC2087].

# File lib/net/imap.rb, line 1645
def getquotaroot(mailbox)
  synchronize do
    send_command("GETQUOTAROOT", mailbox)
    result = []
    result.concat(clear_responses("QUOTAROOT"))
    result.concat(clear_responses("QUOTA"))
    return result
  end
end
id(client_id=nil) click to toggle source

Sends an ID command [RFC2971 §3.1] and returns a hash of the server’s response, or nil if the server does not identify itself.

Note that the user should first check if the server supports the ID capability. For example:

if capable?(:ID)
  id = imap.id(
    name: "my IMAP client (ruby)",
    version: MyIMAP::VERSION,
    "support-url": "mailto:bugs@example.com",
    os: RbConfig::CONFIG["host_os"],
  )
end

See [ID] for field definitions.

Capabilities

The server’s capabilities must include ID [RFC2971].

# File lib/net/imap.rb, line 1130
def id(client_id=nil)
  synchronize do
    send_command("ID", ClientID.new(client_id))
    clear_responses("ID").last
  end
end
idle(timeout = nil, &response_handler) click to toggle source

Sends an IDLE command [RFC2177 §3] [IMAP4rev2 §6.3.13] that waits for notifications of new or expunged messages. Yields responses from the server during the IDLE.

Use idle_done to leave IDLE.

If timeout is given, this method returns after timeout seconds passed. timeout can be used for keep-alive. For example, the following code checks the connection for each 60 seconds.

loop do
  imap.idle(60) do |response|
    do_something_with(response)
    imap.idle_done if some_condition?(response)
  end
end

Returns the server’s response to indicate the IDLE state has ended. Returns nil if the server does not respond to idle_done within config.idle_response_timeout seconds.

Related: idle_done, noop, check

Capabilities

The server’s capabilities must include IDLE [RFC2177].

# File lib/net/imap.rb, line 2620
def idle(timeout = nil, &response_handler)
  raise LocalJumpError, "no block given" unless response_handler

  response = nil

  synchronize do
    tag = Thread.current[:net_imap_tag] = generate_tag
    put_string("#{tag} IDLE#{CRLF}")

    begin
      add_response_handler(&response_handler)
      @idle_done_cond = new_cond
      @idle_done_cond.wait(timeout)
      @idle_done_cond = nil
      if @receiver_thread_terminating
        raise @exception || Net::IMAP::Error.new("connection closed")
      end
    ensure
      unless @receiver_thread_terminating
        remove_response_handler(response_handler)
        put_string("DONE#{CRLF}")
        response = get_tagged_response(tag, "IDLE", idle_response_timeout)
      end
    end
  end

  return response
end
idle_done click to toggle source

Leaves IDLE, allowing idle to return.

If the server does not respond within config.idle_response_timeout seconds, idle will return nil.

Related: idle

# File lib/net/imap.rb, line 2656
def idle_done
  synchronize do
    if @idle_done_cond.nil?
      raise Net::IMAP::Error, "not during IDLE"
    end
    @idle_done_cond.signal
  end
end
idle_response_timeout click to toggle source

Seconds to wait until an IDLE response is received.

# File lib/net/imap.rb, line 782
def idle_response_timeout; config.idle_response_timeout end
list(refname, mailbox) click to toggle source

Sends a LIST command [IMAP4rev1 §6.3.8] and returns a subset of names from the complete set of all names available to the client. refname provides a context (for instance, a base directory in a directory-based mailbox hierarchy). mailbox specifies a mailbox or (via wildcards) mailboxes under that context. Two wildcards may be used in mailbox: "*", which matches all characters including the hierarchy delimiter (for instance, “/” on a UNIX-hosted directory-based mailbox hierarchy); and "%", which matches all characters except the hierarchy delimiter.

If refname is empty, mailbox is used directly to determine which mailboxes to match. If mailbox is empty, the root name of refname and the hierarchy delimiter are returned.

The return value is an array of MailboxList.

Related: lsub, MailboxList

For example:
imap.create("foo/bar")
imap.create("foo/baz")
p imap.list("", "foo/%")
#=> [#<Net::IMAP::MailboxList attr=[:Noselect], delim="/", name="foo/">, \\
     #<Net::IMAP::MailboxList attr=[:Noinferiors, :Marked], delim="/", name="foo/bar">, \\
     #<Net::IMAP::MailboxList attr=[:Noinferiors], delim="/", name="foo/baz">]
# File lib/net/imap.rb, line 1526
def list(refname, mailbox)
  synchronize do
    send_command("LIST", refname, mailbox)
    clear_responses("LIST")
  end
end
login(user, password) click to toggle source

Sends a LOGIN command [IMAP4rev1 §6.2.3] to identify the client and carries the plaintext password authenticating this user. If successful, the connection enters the “authenticated” state.

Using authenticate should be preferred over login. The LOGIN command is not the same as authenticate with the “LOGIN” mechanism.

A Net::IMAP::NoResponseError is raised if authentication fails.

Related: authenticate, starttls

Capabilities

An IMAP client MUST NOT call login when the server advertises the LOGINDISABLED capability. By default, Net::IMAP will raise a LoginDisabledError when that capability is present. See Config#enforce_logindisabled.

Server capabilities may change after starttls, login, and authenticate. Cached capabilities must be invalidated after this method completes. The TaggedResponse to login may include updated capabilities in its ResponseCode.

# File lib/net/imap.rb, line 1367
def login(user, password)
  if enforce_logindisabled? && capability?("LOGINDISABLED")
    raise LoginDisabledError
  end
  send_command("LOGIN", user, password)
    .tap { @capabilities = capabilities_from_resp_code _1 }
end
logout click to toggle source

Sends a LOGOUT command [IMAP4rev1 §6.1.3] to inform the command to inform the server that the client is done with the connection.

Related: disconnect, logout!

# File lib/net/imap.rb, line 1158
def logout
  send_command("LOGOUT")
end
logout! click to toggle source

Calls logout then, after receiving the TaggedResponse for the LOGOUT, calls disconnect. Returns the TaggedResponse from LOGOUT. Returns nil when the client is already disconnected, in contrast to logout which raises an exception.

If logout raises a StandardError, a warning will be printed but the exception will not be re-raised.

This is useful in situations where the connection must be dropped, for example for security or after tests. If logout errors need to be handled, use logout and disconnect instead.

Related: logout, disconnect

# File lib/net/imap.rb, line 1175
def logout!
  logout unless disconnected?
rescue => ex
  warn "%s during <Net::IMAP %s:%s> logout!: %s" % [
    ex.class, host, port, ex
  ]
ensure
  disconnect
end
lsub(refname, mailbox) click to toggle source

Sends a LSUB command [IMAP4rev1 §6.3.9] and returns a subset of names from the set of names that the user has declared as being “active” or “subscribed.” refname and mailbox are interpreted as for list.

The return value is an array of MailboxList objects.

Related: subscribe, unsubscribe, list, MailboxList

# File lib/net/imap.rb, line 1737
def lsub(refname, mailbox)
  synchronize do
    send_command("LSUB", refname, mailbox)
    clear_responses("LSUB")
  end
end
move(set, mailbox) click to toggle source

Sends a MOVE command [RFC6851 §3.1] [IMAP4rev2 §6.4.8] to move the specified message(s) to the end of the specified destination mailbox. The set parameter is a number, an array of numbers, or a Range object. The number is a message sequence number.

Related: uid_move

Capabilities

The server’s capabilities must include MOVE [RFC6851].

If UIDPLUS [RFC4315] is supported, the server’s response should include a COPYUID response code with UIDPlusData. This will report the UIDVALIDITY of the destination mailbox, the UID set of the source messages, and the assigned UID set of the moved messages.

# File lib/net/imap.rb, line 2401
def move(set, mailbox)
  copy_internal("MOVE", set, mailbox)
end
namespace click to toggle source

Sends a NAMESPACE command [RFC2342 §5] and returns the namespaces that are available. The NAMESPACE command allows a client to discover the prefixes of namespaces used by a server for personal mailboxes, other users’ mailboxes, and shared mailboxes.

The return value is a Namespaces object which has personal, other, and shared fields, each an array of Namespace objects. These arrays will be empty when the server responds with nil.

Many IMAP servers are configured with the default personal namespaces as ("" "/"): no prefix and the “/” hierarchy delimiter. In that common case, the naive client may not have any trouble naming mailboxes. But many servers are configured with the default personal namespace as e.g. ("INBOX." "."), placing all personal folders under INBOX, with “.” as the hierarchy delimiter. If the client does not check for this, but naively assumes it can use the same folder names for all servers, then folder creation (and listing, moving, etc) can lead to errors.

From RFC2342:

Although typically a server will support only a single Personal Namespace, and a single Other User’s Namespace, circumstances exist where there MAY be multiples of these, and a client MUST be prepared for them. If a client is configured such that it is required to create a certain mailbox, there can be circumstances where it is unclear which Personal Namespaces it should create the mailbox in. In these situations a client SHOULD let the user select which namespaces to create the mailbox in.

Related: list, Namespaces, Namespace

For example:
if capable?("NAMESPACE")
  namespaces = imap.namespace
  if namespace = namespaces.personal.first
    prefix = namespace.prefix  # e.g. "" or "INBOX."
    delim  = namespace.delim   # e.g. "/" or "."
    # personal folders should use the prefix and delimiter
    imap.create(prefix + "foo")
    imap.create(prefix + "bar")
    imap.create(prefix + %w[path to my folder].join(delim))
  end
end
Capabilities

The server’s capabilities must include NAMESPACE [RFC2342].

# File lib/net/imap.rb, line 1583
def namespace
  synchronize do
    send_command("NAMESPACE")
    clear_responses("NAMESPACE").last
  end
end
noop click to toggle source

Sends a NOOP command [IMAP4rev1 §6.1.2] to the server.

This allows the server to send unsolicited untagged EXPUNGE responses, but does not execute any client request. IMAP servers are permitted to send unsolicited untagged responses at any time, except for EXPUNGE:

Related: idle, check

# File lib/net/imap.rb, line 1149
def noop
  send_command("NOOP")
end
open_timeout click to toggle source

Seconds to wait until a connection is opened. If the IMAP object cannot open a connection within this time, it raises a Net::OpenTimeout exception. The default value is 30 seconds.

# File lib/net/imap.rb, line 779
def open_timeout; config.open_timeout end
remove_response_handler(handler) click to toggle source

Removes the response handler.

Related: add_response_handler, response_handlers

# File lib/net/imap.rb, line 2878
def remove_response_handler(handler)
  synchronize do
    @response_handlers.delete(handler)
  end
end
rename(mailbox, newname) click to toggle source

Sends a RENAME command [IMAP4rev1 §6.3.5] to change the name of the mailbox to newname.

A Net::IMAP::NoResponseError is raised if a mailbox with the name mailbox cannot be renamed to newname for whatever reason; for instance, because mailbox does not exist, or because there is already a mailbox with the name newname.

Related: create, delete

# File lib/net/imap.rb, line 1467
def rename(mailbox, newname)
  send_command("RENAME", mailbox, newname)
end
response_handlers click to toggle source

Returns all response handlers, including those that are added internally by commands. Each response handler will be called with every new UntaggedResponse, TaggedResponse, and ContinuationRequest.

Response handlers are called with a mutex inside the receiver thread. New responses cannot be processed and commands from other threads must wait until all response_handlers return. An exception will shut-down the receiver thread and close the connection.

For thread-safety, the returned array is a frozen copy of the internal array.

Related: add_response_handler, remove_response_handler

# File lib/net/imap.rb, line 2851
def response_handlers
  synchronize { @response_handlers.clone.freeze }
end
responses -> hash of {String → Array} (see config.responses_without_block) click to toggle source
responses(type) → frozen array
responses {|hash| ...} → block result
responses(type) {|array| ...} → block result

Yields or returns unhandled server responses. Unhandled responses are stored in a hash, with arrays of UntaggedResponse#data keyed by UntaggedResponse#name and non-nil untagged ResponseCode#data keyed by ResponseCode#name.

When a block is given, yields unhandled responses and returns the block’s result. Without a block, returns the unhandled responses.

With type

Yield or return only the array of responses for that type. When no block is given, the returned array is a frozen copy.

Without type

Yield or return the entire responses hash.

When no block is given, the behavior is determined by Config#responses_without_block:

:silence_deprecation_warning (original behavior)

Returns the mutable responses hash (without any warnings). This is not thread-safe.

:warn (default since v0.5)

Prints a warning and returns the mutable responses hash. This is not thread-safe.

:frozen_dup (planned default for v0.6)

Returns a frozen copy of the unhandled responses hash, with frozen array values.

:raise

Raise an ArgumentError with the deprecation warning.

For example:

imap.select("inbox")
p imap.responses("EXISTS").last
#=> 2
p imap.responses("UIDNEXT", &:last)
#=> 123456
p imap.responses("UIDVALIDITY", &:last)
#=> 968263756
p imap.responses {|responses|
  {
    exists:      responses.delete("EXISTS").last,
    uidnext:     responses.delete("UIDNEXT").last,
    uidvalidity: responses.delete("UIDVALIDITY").last,
  }
}
#=> {:exists=>2, :uidnext=>123456, :uidvalidity=>968263756}
# "EXISTS", "UIDNEXT", and "UIDVALIDITY" have been removed:
p imap.responses(&:keys)
#=> ["FLAGS", "OK", "PERMANENTFLAGS", "RECENT", "HIGHESTMODSEQ"]

Related: extract_responses, clear_responses, response_handlers, greeting

Thread safety

Note: Access to the responses hash is synchronized for thread-safety. The receiver thread and response_handlers cannot process new responses until the block completes. Accessing either the response hash or its response type arrays outside of the block is unsafe. They can be safely updated inside the block. Consider using clear_responses or extract_responses instead.

Net::IMAP will add and remove responses from the responses hash and its array values, in the calling threads for commands and in the receiver thread, but will not modify any responses after adding them to the responses hash.

Clearing responses

Previously unhandled responses are automatically cleared before entering a mailbox with select or examine. Long-lived connections can receive many unhandled server responses, which must be pruned or they will continually consume more memory. Update or clear the responses hash or arrays inside the block, or remove responses with extract_responses, clear_responses, or add_response_handler.

Missing responses

Only non-nil data is stored. Many important response codes have no data of their own, but are used as “tags” on the ResponseText object they are attached to. ResponseText will be accessible by its response types: “OK”, “NO”, “BAD”, “BYE”, or “PREAUTH”.

TaggedResponse#data is not saved to responses, nor is any ResponseCode#data on tagged responses. Although some command methods do return the TaggedResponse directly, add_response_handler must be used to handle all response codes.

# File lib/net/imap.rb, line 2767
def responses(type = nil)
  if block_given?
    synchronize { yield(type ? @responses[type.to_s.upcase] : @responses) }
  elsif type
    synchronize { @responses[type.to_s.upcase].dup.freeze }
  else
    case config.responses_without_block
    when :raise
      raise ArgumentError, RESPONSES_DEPRECATION_MSG
    when :warn
      warn(RESPONSES_DEPRECATION_MSG, uplevel: 1, category: :deprecated)
    when :frozen_dup
      synchronize {
        responses = @responses.transform_values(&:freeze)
        responses.default_proc = nil
        responses.default = [].freeze
        return responses.freeze
      }
    end
    @responses
  end
end
select(mailbox, condstore: false) click to toggle source

Sends a SELECT command [IMAP4rev1 §6.3.1] to select a mailbox so that messages in the mailbox can be accessed.

After you have selected a mailbox, you may retrieve the number of items in that mailbox from imap.responses("EXISTS", &:last), and the number of recent messages from imap.responses("RECENT", &:last). Note that these values can change if new messages arrive during a session or when existing messages are expunged; see add_response_handler for a way to detect these events.

When the condstore keyword argument is true, the server is told to enable the extension. If mailbox supports persistence of mod-sequences, the HIGHESTMODSEQ ResponseCode will be sent as an untagged response to select and all ‘FETCH` responses will include FetchData#modseq. Otherwise, the NOMODSEQ ResponseCode will be sent.

A Net::IMAP::NoResponseError is raised if the mailbox does not exist or is for some reason non-selectable.

Related: examine

Capabilities

If [UIDPLUS] is supported, the server may return an untagged “NO” response with a “UIDNOTSTICKY” response code indicating that the mailstore does not support persistent UIDs:

imap.responses("NO", &:last)&.code&.name == "UIDNOTSTICKY"

If [CONDSTORE] is supported, the condstore keyword parameter may be used.

imap.select("mbox", condstore: true)
modseq = imap.responses("HIGHESTMODSEQ", &:last)
# File lib/net/imap.rb, line 1408
def select(mailbox, condstore: false)
  args = ["SELECT", mailbox]
  args << ["CONDSTORE"] if condstore
  synchronize do
    @responses.clear
    send_command(*args)
  end
end
setacl(mailbox, user, rights) click to toggle source

Sends a SETACL command [RFC4314 §3.1] along with mailbox, user and the rights that user is to have on that mailbox. If rights is nil, then that user will be stripped of any rights to that mailbox.

Related: getacl

Capabilities

The server’s capabilities must include ACL [RFC4314].

# File lib/net/imap.rb, line 1704
def setacl(mailbox, user, rights)
  if rights.nil?
    send_command("SETACL", mailbox, user, "")
  else
    send_command("SETACL", mailbox, user, rights)
  end
end
setquota(mailbox, quota) click to toggle source

Sends a SETQUOTA command [RFC2087 §4.1] along with the specified mailbox and quota. If quota is nil, then quota will be unset for that mailbox. Typically one needs to be logged in as a server admin for this to work.

Related: getquota, getquotaroot

Capabilities

The server’s capabilities must include QUOTA [RFC2087].

# File lib/net/imap.rb, line 1684
def setquota(mailbox, quota)
  if quota.nil?
    data = '()'
  else
    data = '(STORAGE ' + quota.to_s + ')'
  end
  send_command("SETQUOTA", mailbox, RawData.new(data))
end
sort(sort_keys, search_keys, charset) click to toggle source

Sends a SORT command [RFC5256 §3] to search a mailbox for messages that match search_keys and return an array of message sequence numbers, sorted by sort_keys. search_keys are interpreted the same as for search.

Related: uid_sort, search, uid_search, thread, uid_thread

For example:
p imap.sort(["FROM"], ["ALL"], "US-ASCII")
#=> [1, 2, 3, 5, 6, 7, 8, 4, 9]
p imap.sort(["DATE"], ["SUBJECT", "hello"], "US-ASCII")
#=> [6, 7, 8, 1]
Capabilities

The server’s capabilities must include SORT [RFC5256].

# File lib/net/imap.rb, line 2445
def sort(sort_keys, search_keys, charset)
  return sort_internal("SORT", sort_keys, search_keys, charset)
end
starttls(**options) click to toggle source

Sends a STARTTLS command [IMAP4rev1 §6.2.1] to start a TLS session.

Any options are forwarded directly to OpenSSL::SSL::SSLContext#set_params; the keys are names of attribute assignment methods on SSLContext.

See DeprecatedClientOptions#starttls for deprecated arguments.

This method returns after TLS negotiation and hostname verification are both successful. Any error indicates that the connection has not been secured.

Note:

Any response_handlers added before STARTTLS should be aware that the TaggedResponse to STARTTLS is sent clear-text, before TLS negotiation. TLS starts immediately after that response. Any response code sent with the response (e.g. CAPABILITY) is insecure and cannot be trusted.

Related: Net::IMAP.new, login, authenticate

Capability

Clients should not call starttls unless the server advertises the STARTTLS capability.

Server capabilities may change after starttls, login, and authenticate. Cached capabilities will be cleared when this method completes.

# File lib/net/imap.rb, line 1215
def starttls(**options)
  @ssl_ctx_params, @ssl_ctx = build_ssl_ctx(options)
  send_command("STARTTLS") do |resp|
    if resp.kind_of?(TaggedResponse) && resp.name == "OK"
      clear_cached_capabilities
      clear_responses
      start_tls_session
    end
  end
end
status(mailbox, attr) click to toggle source

Sends a STATUS command [IMAP4rev1 §6.3.10] and returns the status of the indicated mailbox. attr is a list of one or more attributes whose statuses are to be requested.

The return value is a hash of attributes. Most status attributes return integer values, but some return other value types (documented below).

A Net::IMAP::NoResponseError is raised if status values for mailbox cannot be returned; for instance, because it does not exist.

Supported attributes
MESSAGES

The number of messages in the mailbox.

UIDNEXT

The next unique identifier value of the mailbox.

UIDVALIDITY

The unique identifier validity value of the mailbox.

UNSEEN

The number of messages without the \Seen flag.

DELETED

The number of messages with the \Deleted flag.

SIZE

The approximate size of the mailbox—must be greater than or equal to the sum of all messages’ RFC822.SIZE fetch item values.

HIGHESTMODSEQ

The highest mod-sequence value of all messages in the mailbox. See CONDSTORE [RFC7162].

MAILBOXID

A server-allocated unique string identifier for the mailbox. See OBJECTID [RFC8474].

RECENT

The number of messages with the \Recent flag. NOTE: RECENT was removed from IMAP4rev2.

Unsupported attributes may be requested. The attribute value will be either an Integer or an ExtensionData object.

For example:
p imap.status("inbox", ["MESSAGES", "RECENT"])
#=> {"RECENT"=>0, "MESSAGES"=>44}
Capabilities

SIZE requires the server’s capabilities to include either IMAP4rev2 or STATUS=SIZE [RFC8483].

DELETED requires the server’s capabilities to include IMAP4rev2.

HIGHESTMODSEQ requires the server’s capabilities to include CONDSTORE [RFC7162].

MAILBOXID requires the server’s capabilities to include OBJECTID [RFC8474].

# File lib/net/imap.rb, line 1804
def status(mailbox, attr)
  synchronize do
    send_command("STATUS", mailbox, attr)
    clear_responses("STATUS").last&.attr
  end
end
store(set, attr, value, unchangedsince: nil) → array of FetchData click to toggle source

Sends a STORE command [IMAP4rev1 §6.4.6] to alter data associated with messages in the mailbox, in particular their flags.

set is a number, an array of numbers, or a Range object. Each number is a message sequence number.

attr is the name of a data item to store. The semantics of value varies based on attr:

  • When attr is "FLAGS", the flags in value replace the message’s flag list.

  • When attr is "+FLAGS", the flags in value are added to the flags for the message.

  • When attr is "-FLAGS", the flags in value are removed from the message.

unchangedsince is an optional integer mod-sequence. It prohibits any changes to messages with mod-sequence greater than the specified unchangedsince value. A SequenceSet of any messages that fail this check will be returned in a MODIFIED ResponseCode.

The return value is an array of FetchData.

Related: uid_store

For example:
p imap.store(6..8, "+FLAGS", [:Deleted])
#=> [#<Net::IMAP::FetchData seqno=6, attr={"FLAGS"=>[:Seen, :Deleted]}>,
     #<Net::IMAP::FetchData seqno=7, attr={"FLAGS"=>[:Seen, :Deleted]}>,
     #<Net::IMAP::FetchData seqno=8, attr={"FLAGS"=>[:Seen, :Deleted]}>]
Capabilities

Extensions may define new data items to be used with store.

The server’s capabilities must include CONDSTORE [RFC7162] in order to use the unchangedsince argument. Using unchangedsince implicitly enables the CONDSTORE extension.

# File lib/net/imap.rb, line 2329
def store(set, attr, flags, unchangedsince: nil)
  store_internal("STORE", set, attr, flags, unchangedsince: unchangedsince)
end
subscribe(mailbox) click to toggle source

Sends a SUBSCRIBE command [IMAP4rev1 §6.3.6] to add the specified mailbox name to the server’s set of “active” or “subscribed” mailboxes as returned by lsub.

A Net::IMAP::NoResponseError is raised if mailbox cannot be subscribed to; for instance, because it does not exist.

Related: unsubscribe, lsub, list

# File lib/net/imap.rb, line 1479
def subscribe(mailbox)
  send_command("SUBSCRIBE", mailbox)
end
thread(algorithm, search_keys, charset) click to toggle source

Sends a THREAD command [RFC5256 §3] to search a mailbox and return message sequence numbers in threaded format, as a ThreadMember tree. search_keys are interpreted the same as for search.

The supported algorithms are:

ORDEREDSUBJECT

split into single-level threads according to subject, ordered by date.

REFERENCES

split into threads by parent/child relationships determined by which message is a reply to which.

Unlike search, charset is a required argument. US-ASCII and UTF-8 are sample values.

Related: uid_thread, search, uid_search, sort, uid_sort

Capabilities

The server’s capabilities must include THREAD [RFC5256].

# File lib/net/imap.rb, line 2485
def thread(algorithm, search_keys, charset)
  return thread_internal("THREAD", algorithm, search_keys, charset)
end
tls_verified? click to toggle source

Returns true after the TLS negotiation has completed and the remote hostname has been verified. Returns false when TLS has been established but peer verification was disabled.

# File lib/net/imap.rb, line 954
def tls_verified?; @tls_verified end
uid_copy(set, mailbox) click to toggle source

Sends a UID COPY command [IMAP4rev1 §6.4.8] to copy the specified message(s) to the end of the specified destination mailbox.

Similar to copy, but set contains unique identifiers.

Capabilities

UIDPLUS affects uid_copy the same way it affects copy.

# File lib/net/imap.rb, line 2378
def uid_copy(set, mailbox)
  copy_internal("UID COPY", set, mailbox)
end
uid_expunge(uid_set) click to toggle source

Sends a UID EXPUNGE command [RFC4315 §2.1] [IMAP4rev2 §6.4.9] to permanently remove all messages that have both the \Deleted flag set and a UID that is included in uid_set.

By using uid_expunge instead of expunge when resynchronizing with the server, the client can ensure that it does not inadvertantly remove any messages that have been marked as \Deleted by other clients between the time that the client was last connected and the time the client resynchronizes.

Note:

Although the command takes a set of UIDs for its argument, the server still returns regular EXPUNGE responses, which contain a sequence number. These will be deleted from responses and this method returns them as an array of sequence number integers.

Related: expunge

Capabilities

The server’s capabilities must include UIDPLUS [RFC4315].

# File lib/net/imap.rb, line 1925
def uid_expunge(uid_set)
  synchronize do
    send_command("UID EXPUNGE", SequenceSet.new(uid_set))
    clear_responses("EXPUNGE")
  end
end
uid_fetch(set, attr, changedsince: nil) → array of FetchData click to toggle source

Sends a UID FETCH command [IMAP4rev1 §6.4.8] to retrieve data associated with a message in the mailbox.

Similar to fetch, but the set parameter contains unique identifiers instead of message sequence numbers.

Note: Servers MUST implicitly include the UID message data item as part of any FETCH response caused by a UID command, regardless of whether a UID was specified as a message data item to the FETCH.

Related: fetch, FetchData

Capabilities

Same as fetch.

# File lib/net/imap.rb, line 2282
def uid_fetch(set, attr, mod = nil, changedsince: nil)
  fetch_internal("UID FETCH", set, attr, mod, changedsince: changedsince)
end
uid_move(set, mailbox) click to toggle source

Sends a UID MOVE command [RFC6851 §3.2] [IMAP4rev2 §6.4.9] to move the specified message(s) to the end of the specified destination mailbox.

Similar to move, but set contains unique identifiers.

Related: move

Capabilities

Same as move: The server’s capabilities must include MOVE [RFC6851]. UIDPLUS also affects uid_move the same way it affects move.

# File lib/net/imap.rb, line 2419
def uid_move(set, mailbox)
  copy_internal("UID MOVE", set, mailbox)
end
uid_sort(sort_keys, search_keys, charset) click to toggle source

Sends a UID SORT command [RFC5256 §3] to search a mailbox for messages that match search_keys and return an array of unique identifiers, sorted by sort_keys. search_keys are interpreted the same as for search.

Related: sort, search, uid_search, thread, uid_thread

Capabilities

The server’s capabilities must include SORT [RFC5256].

# File lib/net/imap.rb, line 2460
def uid_sort(sort_keys, search_keys, charset)
  return sort_internal("UID SORT", sort_keys, search_keys, charset)
end
uid_store(set, attr, value, unchangedsince: nil) → array of FetchData click to toggle source

Sends a UID STORE command [IMAP4rev1 §6.4.8] to alter data associated with messages in the mailbox, in particular their flags.

Similar to store, but set contains unique identifiers instead of message sequence numbers.

Related: store

Capabilities

Same as store.

# File lib/net/imap.rb, line 2347
def uid_store(set, attr, flags, unchangedsince: nil)
  store_internal("UID STORE", set, attr, flags, unchangedsince: unchangedsince)
end
uid_thread(algorithm, search_keys, charset) click to toggle source

Sends a UID THREAD command [RFC5256 §3] Similar to thread, but returns unique identifiers instead of message sequence numbers.

Related: thread, search, uid_search, sort, uid_sort

Capabilities

The server’s capabilities must include THREAD [RFC5256].

# File lib/net/imap.rb, line 2499
def uid_thread(algorithm, search_keys, charset)
  return thread_internal("UID THREAD", algorithm, search_keys, charset)
end
unselect click to toggle source

Sends an UNSELECT command [RFC3691 §2] [IMAP4rev2 §6.4.2] to free the session resources for a mailbox and return to the “authenticated” state. This is the same as close, except that \Deleted messages are not removed from the mailbox.

Related: close

Capabilities

The server’s capabilities must include UNSELECT [RFC3691].

# File lib/net/imap.rb, line 1884
def unselect
  send_command("UNSELECT")
end
unsubscribe(mailbox) click to toggle source

Sends an UNSUBSCRIBE command [IMAP4rev1 §6.3.7] to remove the specified mailbox name from the server’s set of “active” or “subscribed” mailboxes.

A Net::IMAP::NoResponseError is raised if mailbox cannot be unsubscribed from; for instance, because the client is not currently subscribed to it.

Related: subscribe, lsub, list

# File lib/net/imap.rb, line 1492
def unsubscribe(mailbox)
  send_command("UNSUBSCRIBE", mailbox)
end
xlist(refname, mailbox) click to toggle source

Sends a XLIST command, and returns a subset of names from the complete set of all names available to the client. refname provides a context (for instance, a base directory in a directory-based mailbox hierarchy). mailbox specifies a mailbox or (via wildcards) mailboxes under that context. Two wildcards may be used in mailbox: ‘*’, which matches all characters including the hierarchy delimiter (for instance, ‘/’ on a UNIX-hosted directory-based mailbox hierarchy); and ‘%’, which matches all characters except the hierarchy delimiter.

If refname is empty, mailbox is used directly to determine which mailboxes to match. If mailbox is empty, the root name of refname and the hierarchy delimiter are returned.

The XLIST command is like the LIST command except that the flags returned refer to the function of the folder/mailbox, e.g. :Sent

The return value is an array of MailboxList objects. For example:

imap.create("foo/bar")
imap.create("foo/baz")
p imap.xlist("", "foo/%")
#=> [#<Net::IMAP::MailboxList attr=[:Noselect], delim="/", name="foo/">, \\
     #<Net::IMAP::MailboxList attr=[:Noinferiors, :Marked], delim="/", name="foo/bar">, \\
     #<Net::IMAP::MailboxList attr=[:Noinferiors], delim="/", name="foo/baz">]

Related: list, MailboxList

Capabilities

The server’s capabilities must include XLIST, a deprecated Gmail extension (replaced by SPECIAL-USE).

# File lib/net/imap.rb, line 1627
def xlist(refname, mailbox)
  synchronize do
    send_command("XLIST", refname, mailbox)
    clear_responses("XLIST")
  end
end

Basic Mailbox Attributes

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Mailbox name attributes will be returned in list responses. Base attributes must be returned according to the server’s capabilities.

IMAP4 specifies that all mailbox name attributes, including future extensions, begin with "\". Net::IMAP returns all mailbox attributes as symbols, without the "\" prefix.

Mailbox name attributes are not case-sensitive. The current implementation normalizes mailbox attribute case using String#capitalize, such as :Noselect (not :NoSelect). The constants (such as NO_SELECT) can also be used for comparison. The constants have been defined both with and without underscores between words.

The descriptions here were copied from [RFC-9051 §7.3.1].

Other mailbox name attributes can be found in the IANA IMAP Mailbox Name Attributes registry.

Constants

HASCHILDREN

Alias for HAS_CHILDREN, to match the IMAP spelling.

HASNOCHILDREN

Alias for HAS_NO_CHILDREN, to match the IMAP spelling.

HAS_CHILDREN

The presence of this attribute indicates that the mailbox has child mailboxes. A server SHOULD NOT set this attribute if there are child mailboxes and the user does not have permission to access any of them. In this case, \HasNoChildren SHOULD be used. In many cases, however, a server may not be able to efficiently compute whether a user has access to any child mailboxes. Note that even though the \HasChildren attribute for a mailbox must be correct at the time of processing the mailbox, a client must be prepared to deal with a situation when a mailbox is marked with the \HasChildren attribute, but no child mailbox appears in the response to the list command. This might happen, for example, due to child mailboxes being deleted or made inaccessible to the user (using access control) by another client before the server is able to list them.

It is an error for the server to return both a \HasChildren and a \HasNoChildren attribute in the same list response. A client that encounters a list response with both \HasChildren and \HasNoChildren attributes present should act as if both are absent in the list response.

HAS_NO_CHILDREN

The presence of this attribute indicates that the mailbox has NO child mailboxes that are accessible to the currently authenticated user.

It is an error for the server to return both a \HasChildren and a \HasNoChildren attribute in the same list response. A client that encounters a list response with both \HasChildren and \HasNoChildren attributes present should act as if both are absent in the list response.

Note: the \HasNoChildren attribute should not be confused with the \NoInferiors attribute, which indicates that no child mailboxes exist now and none can be created in the future.

MARKED

The mailbox has been marked “interesting” by the server; the mailbox probably contains messages that have been added since the last time the mailbox was selected.

If it is not feasible for the server to determine whether or not the mailbox is “interesting”, the server SHOULD NOT send either \Marked or \Unmarked. The server MUST NOT send more than one of \Marked, \Unmarked, and \NoSelect for a single mailbox, and it MAY send none of these.

NOINFERIORS

Alias for NO_INFERIORS, to match the IMAP spelling.

NONEXISTENT

The \NonExistent attribute indicates that a mailbox name does not refer to an existing mailbox. Note that this attribute is not meaningful by itself, as mailbox names that match the canonical list pattern but don’t exist must not be returned unless one of the two conditions listed below is also satisfied:

  1. The mailbox name also satisfies the selection criteria (for example, it is subscribed and the “SUBSCRIBED” selection option has been specified).

  2. “RECURSIVEMATCH” has been specified, and the mailbox name has at least one descendant mailbox name that does not match the list pattern and does match the selection criteria.

In practice, this means that the \NonExistent attribute is usually returned with one or more of \Subscribed, \Remote, \HasChildren, or the CHILDINFO extended data item.

The client must treat the presence of the \NonExistent attribute as if the \NoSelect attribute was also sent by the server

NOSELECT

Alias for NO_SELECT, to match the IMAP spelling.

NO_INFERIORS

Mailbox attribute indicating it is not possible for any child levels of hierarchy to exist under this name; no child levels exist now and none can be created in the future children.

The client must treat the presence of the \NoInferiors attribute as if the \HasNoChildren attribute was also sent by the server

NO_SELECT

Mailbox attribute indicating it is not possible to use this name as a selectable mailbox.

REMOTE

The mailbox is a remote mailbox.

SUBSCRIBED

The mailbox name was subscribed to using the subscribe command.

UNMARKED

The mailbox does not contain any additional messages since the last time the mailbox was selected.

If it is not feasible for the server to determine whether or not the mailbox is “interesting”, the server SHOULD NOT send either \Marked or \Unmarked. The server MUST NOT send more than one of \Marked, \Unmarked, and \NoSelect for a single mailbox, and it MAY send none of these.

Mailbox role attributes

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Mailbox name attributes will be returned in list responses. In addition to the base mailbox name attributes defined above, an IMAP server MAY also include any or all of the following attributes that denote “role” (or “special-use”) of a mailbox. These attributes are included along with base attributes defined above. A given mailbox may have none, one, or more than one of these attributes. In some cases, a special use is advice to a client about what to put in that mailbox. In other cases, it’s advice to a client about what to expect to find there.

IMAP4 specifies that all mailbox name attributes, including future extensions, begin with "\". Net::IMAP returns all mailbox attributes as symbols, without the "\" prefix.

The special use attributes were first defined as part of the SPECIAL-USE extension, but servers may return them without including the SPECIAL-USE capability.

The descriptions here were copied from [RFC-9051 §7.3.1].

Other mailbox name attributes can be found in the IANA IMAP Mailbox Name Attributes registry.

Constants

ALL

Mailbox attribute indicating that this mailbox presents all messages in the user’s message store. Implementations MAY omit some messages, such as, perhaps, those in Trash and Junk. When this special use is supported, it is almost certain to represent a virtual mailbox

ARCHIVE

Mailbox attribute indicating that this mailbox is used to archive messages. The meaning of an “archival” mailbox is server dependent; typically, it will be used to get messages out of the inbox, or otherwise keep them out of the user’s way, while still making them accessible

DRAFTS

Mailbox attribute indicating that this mailbox is used to hold draft messages – typically, messages that are being composed but have not yet been sent. In some server implementations, this might be a virtual mailbox, containing messages from other mailboxes that are marked with the “Draft” message flag. Alternatively, this might just be advice that a client put drafts here

JUNK

Mailbox attribute indicating that this mailbox is where messages deemed to be junk mail are held. Some server implementations might put messages here automatically. Alternatively, this might just be advice to a client-side spam filter.

SENT

Mailbox attribute indicating that this mailbox is used to hold copies of messages that have been sent. Some server implementations might put messages here automatically. Alternatively, this might just be advice that a client save sent messages here.

TRASH

Mailbox attribute indicating that this mailbox is used to hold messages that have been deleted or marked for deletion. In some server implementations, this might be a virtual mailbox, containing messages from other mailboxes that are marked with the \Deleted message flag. Alternatively, this might just be advice that a client that chooses not to use the IMAP \Deleted model should use as its trash location. In server implementations that strictly expect the IMAP \Deleted model, this special use is likely not to be supported.

System Flags

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A message has a list of zero or more named tokens, known as “flags”, associated with it. A flag is set by its addition to this list and is cleared by its removal. There are two types of flags in IMAP4rev1 and IMAP4rev2: flags and keywords. A flag of either type can be permanent or session-only.

A “system flag” is a message flag name that is predefined in the IMAP specifications and begins with "\". Net::IMAP returns all system flags as symbols, without the "\" prefix.

The descriptions here were copied from [RFC-9051 §2.3.2]. See also [RFC-3501 §2.3.2], which describes the flags message attribute semantics under IMAP4rev1.

Constants

ANSWERED

Flag indicating a message has been answered.

DELETED

Flag indicating a message has been marked for deletion. This will occur when the mailbox is closed or expunged.

DRAFT

Flag indicating a message is only a draft or work-in-progress version.

FLAGGED

A message flag indicating a message has been flagged for special or urgent attention.

Also a mailbox special use attribute, which indicates that this mailbox presents all messages marked in some way as “important”. When this special use is supported, it is likely to represent a virtual mailbox collecting messages (from other mailboxes) that are marked with the “Flagged” message flag.

RECENT

Flag indicating that the message is “recent,” meaning that this session is the first session in which the client has been notified of this message.

This flag was defined by IMAP4rev1 and is deprecated by IMAP4rev2.

SEEN

Flag indicating a message has been read.