XADM: IMAP4 Client/Server Commands

Article translations Article translations
Article ID: 189325 - View products that this article applies to.
This article was previously published under Q189325
Expand all | Collapse all

SUMMARY

This article explains the Internet Message Access Protocol, Version 4 rev. 1 (IMAP4rev1) features and commands.

MORE INFORMATION

FEATURES:

1. IMAP4rev1 client allows the user to access and manipulate electronic
   messages on a server.
2. IMAP4rev1 permits manipulation of remote message folders, called
   mailboxes, in a way that is functionally equivalent to local mailboxes.
3. IMAP4rev1 also provides the capability for an offline client to re-
   synchronize with the server (see also [IMAP-DISC]).
4. IMAP4rev1 includes operations for creating, deleting, and renaming
   mailboxes.
5. IMAP4rev1 checks for new messages, permanently removes messages, and
   sets and clears flags [RFC-822].
6. IMAP4rev1 does [MIME-IMB] parsing, searching, and selective fetching of
   message attributes, texts, and portions thereof.
7. Messages in IMAP4rev1 are accessed by the use of numbers. These numbers
   are either message sequence numbers or unique identifiers.

COMMANDS and RESPONSES:

   An IMAP4rev1 connection consists of the establishment of a
   client/server network connection, an initial greeting from the
   server, and client/server interactions. These client/server
   interactions consist of a client command, server data, and a server
   completion result response.

Non-Authenticated State
   In a non-authenticated state, the client MUST supply authentication
   credentials before most commands are permitted. This state is
   entered when a connection starts, unless the connection has been pre-
   authenticated.

Authenticated State
   In an authenticated state, the client is authenticated and MUST select a
   mailbox to access before commands that affect messages are permitted.
   This state is entered when a pre-authenticated connection starts, when
   acceptable authentication credentials have been provided, or after an
   error in selecting a mailbox.

CLIENT COMMANDS - ANY STATE:

CAPABILITY Command

   Arguments:  none
   Responses:  REQUIRED untagged response: CAPABILITY
   Result:     OK - capability completed
               BAD - command unknown or arguments invalid

The CAPABILITY command requests a listing of capabilities that the server
supports.

              Example:
              C: abcd CAPABILITY
              S: * CAPABILITY IMAP4rev1 AUTH=KERBEROS_V4
              S: abcd OK CAPABILITY completed


NOOP Command

   Arguments:  none
   Responses:  no specific responses for this command (but see below)
   Result:     OK - noop completed
               BAD - command unknown or arguments invalid

The NOOP command always succeeds. It does nothing.

               Example:
               C: a002 NOOP
               S: a002 OK NOOP completed . . .
               C: a047 NOOP S: * 22 EXPUNGE
               S: * 23 EXISTS S: * 3 RECENT
               S: * 14 FETCH (FLAGS (\Seen \Deleted))
               S: a047 OK NOOP completed

LOGOUT Command

   Arguments:  none
   Responses:  REQUIRED untagged response: BYE
   Result:     OK - logout completed
               BAD - command unknown or arguments invalid

The LOGOUT command informs the server that the client is done with the
connection.
               Example:
               C: A023 LOGOUT
               S: * BYE IMAP4rev1 Server logging out
               S: A023 OK LOGOUT completed (Server and client then close
                  the connection)

CLIENT COMMANDS - NON-AUTHENTICATED STATE:

AUTHENTICATE Command

   Arguments:  authentication mechanism name
   Responses:  continuation data can be requested
   Result:     OK - authenticate completed, now in authenticated state
               NO - authenticate failure: unsupported authentication
                    mechanism, credentials rejected
               BAD - command unknown or arguments invalid,
                    authentication exchange cancelled

The AUTHENTICATE command indicates an authentication mechanism to the
server.
               Example:
               S: * OK KerberosV4 IMAP4rev1 Server
               C: A001 AUTHENTICATE KERBEROS_V4
               S: + AmFYig== C:
               S: + or//EoAADZI= C: DiAF5A4gA+oOIALuBkAAmw==
               S: A001 OK Kerberos V4 authentication successful

LOGIN Command

   Arguments:  user name
               password
   Responses:  no specific responses for this command
   Result:     OK - login completed, now in authenticated state
               NO - login failure: user name or password rejected
               BAD - command unknown or arguments invalid

The LOGIN command identifies the client to the server and carries the plain
text password authenticating this user.

               Example:
               C: a001 LOGIN <username & password>
               S: a001 OK LOGIN completed

CLIENT COMMANDS - AUTHENTICATED STATE:

SELECT Command

   Arguments:  mailbox name
   Responses:  REQUIRED untagged responses: FLAGS, EXISTS, RECENT
               OPTIONAL OK untagged responses: UNSEEN, PERMANENTFLAGS
   Result:     OK - select completed, now in selected state
               NO - select failure, now in authenticated state: no
                    such mailbox, cannot access mailbox
               BAD - command unknown or arguments invalid

The SELECT command selects a mailbox so that messages in the mailbox can be
accessed.

               Example:
               C: A142 SELECT INBOX
               S: * 172 EXISTS
               S: * 1 RECENT
               S: * OK [UNSEEN 12] Message 12 is first unseen
               S: * OK [UIDVALIDITY 3857529045] UIDs valid
               S: * FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
               S: * OK [PERMANENTFLAGS (\Deleted \Seen \*)] Limited
               S: A142 OK [READ-WRITE] SELECT completed

EXAMINE Command

   Arguments:  mailbox name
   Responses:  REQUIRED untagged responses: FLAGS, EXISTS, RECENT
               OPTIONAL OK untagged responses: UNSEEN, PERMANENTFLAGS
   Result:     OK - examine completed, now in selected state
               NO - examine failure, now in authenticated state: no
                    such mailbox, cannot access mailbox
               BAD - command unknown or arguments invalid

The EXAMINE command is identical to SELECT and returns the same output;
however, the selected mailbox is identified as read-only. No changes to the
permanent state of the mailbox, including per-user state, are permitted.

               Example:
               C: A932 EXAMINE <mailboxname>
               S: * 17 EXISTS S: * 2 RECENT
               S: * OK [UNSEEN 8] Message 8 is first unseen
               S: * OK [UIDVALIDITY 3857529045] UIDs valid
               S: * FLAGS (\Answered \Flagged \Deleted \Seen \Draft)
               S: * OK [PERMANENTFLAGS ()] No permanent flags permitted
               S: A932 OK [READ-ONLY] EXAMINE completed

CREATE Command

   Arguments:  mailbox name
   Responses:  no specific responses for this command
   Result:     OK - create completed
               NO - create failure: cannot create mailbox with that name
               BAD - command unknown or arguments invalid

The CREATE command creates a mailbox with the given name. An OK response is
returned only if a new mailbox with that name has been created.

               Example:
               C: A003 CREATE <mailboxname>
               S: A003 OK CREATE completed
               C: A004 CREATE <mailboxname/mailboxname>
               S: A004 OK CREATE completed

DELETE Command

   Arguments:  mailbox name
   Responses:  no specific responses for this command
   Result:     OK - delete completed
               NO - delete failure: cannot delete mailbox with that name
               BAD - command unknown or arguments invalid

The DELETE command permanently removes the mailbox with the given name. A
tagged OK response is returned only if the mailbox has been deleted.

Examples:
 C: A682 LIST "" *                      S: A687 OK DELETE Completed
 S: * LIST () "/" <mailboxname>        C: A82 LIST "" *
 S: * LIST (\Noselect) "/" <mailboxname>     S: * LIST () "." <mailboxname>
 S: * LIST () "/" <mailboxname/<mailboxname> S: * LIST () "." <mailboxname>
 S: A682 OK LIST completed                S: * LIST () "."
                                             <mailboxname.mailboxname>
 C: A683 DELETE <mailboxname>       S: A82 OK LIST completed
 S: A683 OK DELETE completed              C: A83 DELETE <mailboxname>
 C: A684 DELETE <mailboxname>       S: A83 OK DELETE completed
 S: A684 NO Name <mailboxname>      C: A84 DELETE <mailboxname>
 C: A685 DELETE <mailboxname.mailboxname> S: A84 OK DELETE Completed
 S: A685 OK DELETE Completed           C: A85 LIST "" *
 C: A686 LIST "" *                     S: * LIST () "."
                                          <mailboxname.mailboxname>>
 S: * LIST (\Noselect) "/" <mailboxname>     S: A85 OK LIST completed
 S: A686 OK LIST completed                C: A86 LIST "" %
 C: A687 DELETE <mailboxname>       S: * LIST (\Noselect) "." <mailboxname>
                        S: A86 OK LIST completed

RENAME Command

   Arguments:  existing mailbox name
               new mailbox name
   Responses:  no specific responses for this command
   Result:     OK - rename completed
               NO - rename failure: cannot rename mailbox with that name,
                    cannot rename to mailbox with that name
               BAD - command unknown or arguments invalid

The RENAME command changes the name of a mailbox. A tagged OK response is
returned only if the mailbox has been renamed.

Examples:
C: A682 LIST "" *                   S: * LIST (\Noselect) "/" <mailboxname>
S: * LIST () "/" <mailboxname>      S: * LIST () "/"
                                       <mailboxname/<mailboxname>
S: A685 OK LIST completed                    S: Z432 OK LIST completed
S: * LIST (\Noselect) "/" <mailboxname>      C: Z432 LIST "" *
S: * LIST () "/" <mailboxname/mailboxname>   S: * LIST () "." <mailboxname>
S: A682 OK LIST completed           S: * LIST () "."
                                       <mailboxname.mailboxname>
C: A683 RENAME <mailboxname mailboxname>  S: Z432 OK LIST completed
S: A683 OK RENAME completed         C: Z433 RENAME <mailboxname old-
                                       mail>
C: A684 RENAME <mailboxname mailboxname>  S: Z433 OK RENAME completed
S: A684 OK RENAME Completed         C: Z434 LIST "" *
C: A685 LIST "" *                   S: * LIST () "." <mailboxname>
S: * LIST ()                        S: * LIST () "."
                                       <mailboxname.mailboxname>
S: * LIST () "/" <mailboxname>      S: * LIST () "." old-mail
S: Z434 OK LIST completed

SUBSCRIBE Command

   Arguments:  mailbox
   Responses:  no specific responses for this command
   Result:     OK - subscribe completed
               NO - subscribe failure: cannot subscribe to that name
               BAD - command unknown or arguments invalid

The SUBSCRIBE command adds the specified mailbox name to the server's set
of "active" or "subscribed" mailboxes as returned by the LSUB command. This
command returns a tagged OK response only if the subscription is
successful.

               Example:
               C: A002 SUBSCRIBE #<newsgroup>
               S: A002 OK SUBSCRIBE completed


 UNSUBSCRIBE Command

   Arguments:  mailbox name
   Responses:  no specific responses for this command
   Result:     OK - unsubscribe completed
               NO - unsubscribe failure: cannot unsubscribe that name
               BAD - command unknown or arguments invalid

The UNSUBSCRIBE command removes the specified mailbox name from the
server's set of "active" or "subscribed" mailboxes as returned by the LSUB
command. This command returns a tagged OK response only if the
unsubscription is successful.

              Example:
              C: A002 UNSUBSCRIBE #<newsgroup>
              S: A002 OK UNSUBSCRIBE completed

LIST Command

   Arguments:  reference name
               mailbox name with possible wildcards
   Responses:  untagged responses: LIST
   Result:     OK - list completed
               NO - list failure: cannot list that reference or name
               BAD - command unknown or arguments invalid

The LIST command returns a subset of names from the complete set of all
names available to the client.

Examples:
C: A101 LIST "" ""                     C: A103 LIST /usr/staff/<name> ""
S: * LIST (\Noselect) "/" ""              C: * LIST (\Noselect) "/" / 
S: A101 OK LIST Completed              S: A103 OK LIST Completed
C: A102 LIST #<newsgroup> ""           C: A202 LIST ~/Mail/ %
S: * LIST (\Noselect) "." #news.       S: * LIST (\Noselect)
                                          "/"~/Mail/<mailboxname>
S: A102 OK LIST Completed              S: * LIST () "/" ~/Mail/meetings
                                             S: A202 OK LIST completed

LSUB Command

   Arguments:  reference name
               mailbox name with possible wildcards
   Responses:  untagged responses: LSUB
   Result:     OK - lsub completed
               NO - lsub failure: cannot list that reference or name
               BAD - command unknown or arguments invalid

The LSUB command returns a subset of names from the set of names that the
user has declared as being "active" or "subscribed".

               Example:
               C: A002 LSUB "#newsgroup." "newsgroup.*"
               S: * LSUB () "." #news.comp.mail.mime
               S: * LSUB () "." #news.comp.mail.misc
               S: A002 OK LSUB completed

STATUS Command

   Arguments:  mailbox name
               status data item names
   Responses:  untagged responses: STATUS
   Result:     OK - status completed
               NO - status failure: no status for that name
               BAD - command unknown or arguments invalid

The STATUS command requests the status of the indicated mailbox. It does
not change the currently selected mailbox, nor does it affect the state of
any messages in the queried mailbox (in particular, STATUS MUST NOT cause
messages to lose the \Recent flag).

               Example:
               C: A042 STATUS <mailboxname> (UIDNEXT MESSAGES)
               S: * STATUS <mailboxname> (MESSAGES 231 UIDNEXT 44292)
               S: A042 OK STATUS completed

APPEND Command

   Arguments:  mailbox name
               OPTIONAL flag parenthesized list
               OPTIONAL date/time string
               message literal
   Responses:  no specific responses for this command
   Result:     OK - append completed
               NO - append error: cannot append to that mailbox, error
                    in flags or date/time or message text
               BAD - command unknown or arguments invalid

The APPEND command appends the literal argument as a new message to the end
of the specified destination mailbox. This argument SHOULD be in the format
of an [RFC-822] message.

               Example:
               C: A003 APPEND saved-messages (\Seen) {310}
               C: Date: Mon, 7 Feb 1994 21:52:25 -0800 (PST)
               C: From: User Name <username@domainname.COM>
               C: To: username@domainname.com
               C: Message-Id: <B27397-0100000@domainname.COM>
               C: MIME-Version: 1.0
               C: Content-Type: TEXT/PLAIN; CHARSET=US-ASCII
               C: Subject: afternoon meeting
               C: C: Hello <user>, do you think we can meet at 3:30
                  tomorrow?
               S: A003 OK APPEND completed

CLIENT COMMANDS - SELECTED STATE:

CHECK Command

   Arguments:  none
   Responses:  no specific responses for this command
   Result:     OK - check completed
               BAD - command unknown or arguments invalid

The CHECK command requests a checkpoint of the currently selected mailbox.
A checkpoint refers to any implementation-dependent housekeeping associated
with the mailbox (for example, resolving the server's in-memory state of
the mailbox with the state on its disk) that is not normally executed as
part of each command.

               Example:
               C: FXXZ CHECK
               S: FXXZ OK CHECK Completed

CLOSE Command

   Arguments:  none
   Responses:  no specific responses for this command
   Result:     OK - close completed, now in authenticated state
               NO - close failure: no mailbox selected
               BAD - command unknown or arguments invalid

The CLOSE command permanently removes from the currently selected mailbox
all messages that have the \Deleted flag set, and returns to authenticated
state from selected state.

               Example:
               C: A341 CLOSE
               S: A341 OK CLOSE completed

EXPUNGE Command

   Arguments:  none
   Responses:  untagged responses: EXPUNGE
   Result:     OK - expunge completed
               NO - expunge failure: cannot expunge (for example,
                    Permission denied)
               BAD - command unknown or arguments invalid

The EXPUNGE command permanently removes from the currently selected mailbox
all messages that have the \Deleted flag set.

               Example:
               C: A202 EXPUNGE
               S: * 3 EXPUNGE
               S: * 3 EXPUNGE
               S: * 5 EXPUNGE
               S: * 8 EXPUNGE
               S: A202 OK EXPUNGE completed

SEARCH Command

   Arguments:  OPTIONAL [CHARSET] specification
               searching criteria (one or more)
   Responses:  REQUIRED untagged response: SEARCH
   Result:     OK - search completed
               NO - search error: cannot search that [CHARSET] or
                    criteria
               BAD - command unknown or arguments invalid

The SEARCH command searches the mailbox for messages that match the given
searching criteria. Searching criteria consist of one or more search keys:

      <message set>  Messages with message sequence numbers
                     corresponding to the specified message sequence
                     number set.

      ALL            All messages in the mailbox.

      ANSWERED       Messages with the \Answered flag set.

      BCC <string>   Messages that contain the specified string in the
                     envelope structure's BCC field.

      BEFORE <date>  Messages whose internal date is earlier than the
                     specified date.

      BODY <string>  Messages that contain the specified string in the
                     body of the message.

      CC <string>    Messages that contain the specified string in the
                     envelope structure's CC field.

      DELETED        Messages with the \Deleted flag set.

      DRAFT          Messages with the \Draft flag set.

      FLAGGED        Messages with the \Flagged flag set.

      FROM <string>  Messages that contain the specified string in the
                     envelope structure's FROM field.

      HEADER <field-name> <string>
                     Messages that have a header with the specified
                     field-name (as defined in [RFC-822]) and that
                     contain the specified string in the [RFC-822]
                     field-body.

      KEYWORD <flag> Messages with the specified keyword set.

      LARGER <n>     Messages with an [RFC-822] size larger than the
                     specified number of octets.

      NEW            Messages that have the \Recent flag set but not the
                     \Seen flag. This is functionally equivalent to
                     "(RECENT UNSEEN)".

      NOT <search-key>
                     Messages that do not match the specified search key.

      OLD            Messages that do not have the \Recent flag set.
                     This is functionally equivalent to "NOT RECENT" (as
                     opposed to "NOT NEW").

      ON <date>      Messages whose internal date is within the
                     specified date.

      OR <search-key1> <search-key2>
                     Messages that match either search key.

      RECENT         Messages that have the \Recent flag set.

      SEEN           Messages that have the \Seen flag set.

      SENTBEFORE <date>
                     Messages whose [RFC-822] Date: header is earlier
                     than the specified date.

      SENTON <date>  Messages whose [RFC-822] Date: header is within the
                     specified date.

      SENTSINCE <date>
                     Messages whose [RFC-822] Date: header is within or
                     later than the specified date.

      SINCE <date>   Messages whose internal date is within or later
                     than the specified date.

      SMALLER <n>    Messages with an [RFC-822] size smaller than the
                     specified number of octets.

      SUBJECT <string>
                     Messages that contain the specified string in the
                     envelope structure's SUBJECT field.

      TEXT <string>  Messages that contain the specified string in the
                     header or body of the message.

      TO <string>    Messages that contain the specified string in the
                     envelope structure's TO field.

      UID <message set>
                     Messages with unique identifiers corresponding to
                     the specified unique identifier set.

      UNANSWERED     Messages that do not have the \Answered flag set.

      UNDELETED      Messages that do not have the \Deleted flag set.

      UNDRAFT        Messages that do not have the \Draft flag set.

      UNFLAGGED      Messages that do not have the \Flagged flag set.

      UNKEYWORD <flag>
                     Messages that do not have the specified keyword set.

      UNSEEN         Messages that do not have the \Seen flag set.

            Example:
            C: A282 SEARCH FLAGGED SINCE 1-Feb-1994 NOT FROM "<username>"
            S: * SEARCH 2 84 882 S: A282 OK SEARCH completed

FETCH Command

   Arguments:  message set
               message data item names
   Responses:  untagged responses: FETCH
   Result:     OK - fetch completed
               NO - fetch error: cannot fetch that data
               BAD - command unknown or arguments invalid

The FETCH command retrieves data associated with a message in the mailbox.
The currently defined data items that can be fetched are:

      ALL            Macro equivalent to: (FLAGS INTERNALDATE
                     RFC822.SIZE ENVELOPE)

      BODY           Non-extensible form of BODYSTRUCTURE.

      BODY[<section>]<<partial>>
                     The text of a particular body section. The section
                     specification is a set of zero or more part
                     specifiers delimited by periods. A part specifier
                     is either a part number or one of the following:
                     HEADER, HEADER.FIELDS, HEADER.FIELDS.NOT, MIME, and
                     TEXT. An empty section specification refers to the
                     entire message, including the header.

          Example:
          C: A654 FETCH 2:4 (FLAGS BODY[HEADER.FIELDS (DATE FROM)])
          S: * 2 FETCH ....
          S: * 3 FETCH ....
          S: * 4 FETCH ....
          S: A654 OK FETCH completed

STORE Command

   Arguments:  message set
               message data item name
               value for message data item
   Responses:  untagged responses: FETCH
   Result:     OK - store completed
               NO - store error: cannnot store that data
               BAD - command unknown or arguments invalid

The STORE command alters data associated with a message in the mailbox.

          Example:
          C: A003 STORE 2:4 +FLAGS (\Deleted)
          S: * 2 FETCH FLAGS (\Deleted \Seen)
          S: * 3 FETCH FLAGS (\Deleted)
          S: * 4 FETCH FLAGS (\Deleted \Flagged \Seen)
          S: A003 OK STORE completed

COPY Command

   Arguments:  message set
               mailbox name
   Responses:  no specific responses for this command
   Result:     OK - copy completed
               NO - copy error: cannot copy those messages or to that
                    name
               BAD - command unknown or arguments invalid

The COPY command copies the specified message(s) to the end of the
specified destination mailbox. The flags and internal date of the
message(s) SHOULD be preserved in the copy.

               Example:
               C: A003 COPY 2:4 MEETING
               S: A003 OK COPY completed

UID Command

   Arguments:  command name
               command arguments
   Responses:  untagged responses: FETCH, SEARCH
   Result:     OK - UID command completed
               NO - UID command error
               BAD - command unknown or arguments invalid

The UID command has two forms. In the first form, it takes as its arguments
a COPY, FETCH, or STORE command with arguments appropriate for the
associated command. In the second form, the UID command takes a SEARCH
command with SEARCH command arguments.

               Example:
               C: A999 UID FETCH 4827313:4828442 FLAGS
               S: * 23 FETCH (FLAGS (\Seen) UID 4827313)
               S: * 24 FETCH (FLAGS (\Seen) UID 4827943)
               S: * 25 FETCH (FLAGS (\Seen) UID 4828442)
               S: A999 UID FETCH completed
				

Properties

Article ID: 189325 - Last Review: October 28, 2006 - Revision: 4.3
APPLIES TO
  • Microsoft Exchange Server 5.5 Standard Edition
Keywords: 
kbinfo KB189325
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

Give Feedback

 

Contact us for more help

Contact us for more help
Connect with Answer Desk for expert help.
Get more support from smallbusiness.support.microsoft.com