:mod:`imaplib` --- IMAP4 protocol client

========================================

.. module:: imaplib

   :synopsis: IMAP4 protocol client (requires sockets).

.. moduleauthor:: Piers Lauder <piers@communitysolutions.com.au>

.. sectionauthor:: Piers Lauder <piers@communitysolutions.com.au>

.. revised by ESR, January 2000

.. changes for IMAP4_SSL by Tino Lange <Tino.Lange@isg.de>, March 2002

.. changes for IMAP4_stream by Piers Lauder <piers@communitysolutions.com.au>,

   November 2002

.. index::

   pair: IMAP4; protocol

   pair: IMAP4_SSL; protocol

   pair: IMAP4_stream; protocol

This module defines three classes, :class:`IMAP4`, :class:`IMAP4_SSL` and

:class:`IMAP4_stream`, which encapsulate a connection to an IMAP4 server and

implement a large subset of the IMAP4rev1 client protocol as defined in

:rfc:`2060`. It is backward compatible with IMAP4 (:rfc:`1730`) servers, but

note that the ``STATUS`` command is not supported in IMAP4.

Three classes are provided by the :mod:`imaplib` module, :class:`IMAP4` is the

base class:

.. class:: IMAP4([host[, port]])

   This class implements the actual IMAP4 protocol.  The connection is created and

   protocol version (IMAP4 or IMAP4rev1) is determined when the instance is

   initialized. If *host* is not specified, ``''`` (the local host) is used. If

   *port* is omitted, the standard IMAP4 port (143) is used.

Three exceptions are defined as attributes of the :class:`IMAP4` class:

.. exception:: IMAP4.error

   Exception raised on any errors.  The reason for the exception is passed to the

   constructor as a string.

.. exception:: IMAP4.abort

   IMAP4 server errors cause this exception to be raised.  This is a sub-class of

   :exc:`IMAP4.error`.  Note that closing the instance and instantiating a new one

   will usually allow recovery from this exception.

.. exception:: IMAP4.readonly

   This exception is raised when a writable mailbox has its status changed by the

   server.  This is a sub-class of :exc:`IMAP4.error`.  Some other client now has

   write permission, and the mailbox will need to be re-opened to re-obtain write

   permission.

There's also a subclass for secure connections:

.. class:: IMAP4_SSL([host[, port[, keyfile[, certfile]]]])

   This is a subclass derived from :class:`IMAP4` that connects over an SSL

   encrypted socket (to use this class you need a socket module that was compiled

   with SSL support).  If *host* is not specified, ``''`` (the local host) is used.

   If *port* is omitted, the standard IMAP4-over-SSL port (993) is used.  *keyfile*

   and *certfile* are also optional - they can contain a PEM formatted private key

   and certificate chain file for the SSL connection.

The second subclass allows for connections created by a child process:

.. class:: IMAP4_stream(command)

   This is a subclass derived from :class:`IMAP4` that connects to the

   ``stdin/stdout`` file descriptors created by passing *command* to

   ``os.popen2()``.

   .. versionadded:: 2.3

The following utility functions are defined:

.. function:: Internaldate2tuple(datestr)

   Converts an IMAP4 INTERNALDATE string to Coordinated Universal Time. Returns a

   :mod:`time` module tuple.

.. function:: Int2AP(num)

   Converts an integer into a string representation using characters from the set

   [``A`` .. ``P``].

.. function:: ParseFlags(flagstr)

   Converts an IMAP4 ``FLAGS`` response to a tuple of individual flags.

.. function:: Time2Internaldate(date_time)

   Converts a :mod:`time` module tuple to an IMAP4 ``INTERNALDATE`` representation.

   Returns a string in the form: ``"DD-Mmm-YYYY HH:MM:SS +HHMM"`` (including

   double-quotes).

Note that IMAP4 message numbers change as the mailbox changes; in particular,

after an ``EXPUNGE`` command performs deletions the remaining messages are

renumbered. So it is highly advisable to use UIDs instead, with the UID command.

At the end of the module, there is a test section that contains a more extensive

example of usage.

.. seealso::

   Documents describing the protocol, and sources and binaries  for servers

   implementing it, can all be found at the University of Washington's *IMAP

   Information Center* (http://www.washington.edu/imap/).

.. _imap4-objects:

IMAP4 Objects

-------------

All IMAP4rev1 commands are represented by methods of the same name, either

upper-case or lower-case.

All arguments to commands are converted to strings, except for ``AUTHENTICATE``,

and the last argument to ``APPEND`` which is passed as an IMAP4 literal.  If

necessary (the string contains IMAP4 protocol-sensitive characters and isn't

enclosed with either parentheses or double quotes) each string is quoted.

However, the *password* argument to the ``LOGIN`` command is always quoted. If

you want to avoid having an argument string quoted (eg: the *flags* argument to

``STORE``) then enclose the string in parentheses (eg: ``r'(\Deleted)'``).

Each command returns a tuple: ``(type, [data, ...])`` where *type* is usually

``'OK'`` or ``'NO'``, and *data* is either the text from the command response,

or mandated results from the command. Each *data* is either a string, or a

tuple. If a tuple, then the first part is the header of the response, and the

second part contains the data (ie: 'literal' value).

The *message_set* options to commands below is a string specifying one or more

messages to be acted upon.  It may be a simple message number (``'1'``), a range

of message numbers (``'2:4'``), or a group of non-contiguous ranges separated by

commas (``'1:3,6:9'``).  A range can contain an asterisk to indicate an infinite

upper bound (``'3:*'``).

An :class:`IMAP4` instance has the following methods:

.. method:: IMAP4.append(mailbox, flags, date_time, message)

   Append *message* to named mailbox.

.. method:: IMAP4.authenticate(mechanism, authobject)

   Authenticate command --- requires response processing.

   *mechanism* specifies which authentication mechanism is to be used - it should

   appear in the instance variable ``capabilities`` in the form ``AUTH=mechanism``.

   *authobject* must be a callable object::

      data = authobject(response)

   It will be called to process server continuation responses. It should return

   ``data`` that will be encoded and sent to server. It should return ``None`` if

   the client abort response ``*`` should be sent instead.

.. method:: IMAP4.check()

   Checkpoint mailbox on server.

.. method:: IMAP4.close()

   Close currently selected mailbox. Deleted messages are removed from writable

   mailbox. This is the recommended command before ``LOGOUT``.

.. method:: IMAP4.copy(message_set, new_mailbox)

   Copy *message_set* messages onto end of *new_mailbox*.

.. method:: IMAP4.create(mailbox)

   Create new mailbox named *mailbox*.

.. method:: IMAP4.delete(mailbox)

   Delete old mailbox named *mailbox*.

.. method:: IMAP4.deleteacl(mailbox, who)

   Delete the ACLs (remove any rights) set for who on mailbox.

   .. versionadded:: 2.4

.. method:: IMAP4.expunge()

   Permanently remove deleted items from selected mailbox. Generates an ``EXPUNGE``

   response for each deleted message. Returned data contains a list of ``EXPUNGE``

   message numbers in order received.

.. method:: IMAP4.fetch(message_set, message_parts)

   Fetch (parts of) messages.  *message_parts* should be a string of message part

   names enclosed within parentheses, eg: ``"(UID BODY[TEXT])"``.  Returned data

   are tuples of message part envelope and data.

.. method:: IMAP4.getacl(mailbox)

   Get the ``ACL``\ s for *mailbox*. The method is non-standard, but is supported

   by the ``Cyrus`` server.

.. method:: IMAP4.getannotation(mailbox, entry, attribute)

   Retrieve the specified ``ANNOTATION``\ s for *mailbox*. The method is

   non-standard, but is supported by the ``Cyrus`` server.

   .. versionadded:: 2.5

.. method:: IMAP4.getquota(root)

   Get the ``quota`` *root*'s resource usage and limits. This method is part of the

   IMAP4 QUOTA extension defined in rfc2087.

   .. versionadded:: 2.3

.. method:: IMAP4.getquotaroot(mailbox)

   Get the list of ``quota`` ``roots`` for the named *mailbox*. This method is part

   of the IMAP4 QUOTA extension defined in rfc2087.

   .. versionadded:: 2.3

.. method:: IMAP4.list([directory[, pattern]])

   List mailbox names in *directory* matching *pattern*.  *directory* defaults to

   the top-level mail folder, and *pattern* defaults to match anything.  Returned

   data contains a list of ``LIST`` responses.

.. method:: IMAP4.login(user, password)

   Identify the client using a plaintext password. The *password* will be quoted.

.. method:: IMAP4.login_cram_md5(user, password)

   Force use of ``CRAM-MD5`` authentication when identifying the client to protect

   the password.  Will only work if the server ``CAPABILITY`` response includes the

   phrase ``AUTH=CRAM-MD5``.

   .. versionadded:: 2.3

.. method:: IMAP4.logout()

   Shutdown connection to server. Returns server ``BYE`` response.

.. method:: IMAP4.lsub([directory[, pattern]])

   List subscribed mailbox names in directory matching pattern. *directory*

   defaults to the top level directory and *pattern* defaults to match any mailbox.

   Returned data are tuples of message part envelope and data.

.. method:: IMAP4.myrights(mailbox)

   Show my ACLs for a mailbox (i.e. the rights that I have on mailbox).

   .. versionadded:: 2.4

.. method:: IMAP4.namespace()

   Returns IMAP namespaces as defined in RFC2342.

   .. versionadded:: 2.3

.. method:: IMAP4.noop()

   Send ``NOOP`` to server.

.. method:: IMAP4.open(host, port)

   Opens socket to *port* at *host*. The connection objects established by this

   method will be used in the ``read``, ``readline``, ``send``, and ``shutdown``

   methods. You may override this method.

.. method:: IMAP4.partial(message_num, message_part, start, length)

   Fetch truncated part of a message. Returned data is a tuple of message part

   envelope and data.

.. method:: IMAP4.proxyauth(user)

   Assume authentication as *user*. Allows an authorised administrator to proxy

   into any user's mailbox.

   .. versionadded:: 2.3

.. method:: IMAP4.read(size)

   Reads *size* bytes from the remote server. You may override this method.

.. method:: IMAP4.readline()

   Reads one line from the remote server. You may override this method.

.. method:: IMAP4.recent()

   Prompt server for an update. Returned data is ``None`` if no new messages, else

   value of ``RECENT`` response.

.. method:: IMAP4.rename(oldmailbox, newmailbox)

   Rename mailbox named *oldmailbox* to *newmailbox*.

.. method:: IMAP4.response(code)

   Return data for response *code* if received, or ``None``. Returns the given

   code, instead of the usual type.

.. method:: IMAP4.search(charset, criterion[, ...])

   Search mailbox for matching messages.  *charset* may be ``None``, in which case

   no ``CHARSET`` will be specified in the request to the server.  The IMAP

   protocol requires that at least one criterion be specified; an exception will be

   raised when the server returns an error.

   Example::

      # M is a connected IMAP4 instance...

      typ, msgnums = M.search(None, 'FROM', '"LDJ"')

      # or:

      typ, msgnums = M.search(None, '(FROM "LDJ")')

.. method:: IMAP4.select([mailbox[, readonly]])

   Select a mailbox. Returned data is the count of messages in *mailbox*

   (``EXISTS`` response).  The default *mailbox* is ``'INBOX'``.  If the *readonly*

   flag is set, modifications to the mailbox are not allowed.

.. method:: IMAP4.send(data)

   Sends ``data`` to the remote server. You may override this method.

.. method:: IMAP4.setacl(mailbox, who, what)

   Set an ``ACL`` for *mailbox*. The method is non-standard, but is supported by

   the ``Cyrus`` server.

.. method:: IMAP4.setannotation(mailbox, entry, attribute[, ...])

   Set ``ANNOTATION``\ s for *mailbox*. The method is non-standard, but is

   supported by the ``Cyrus`` server.

   .. versionadded:: 2.5

.. method:: IMAP4.setquota(root, limits)

   Set the ``quota`` *root*'s resource *limits*. This method is part of the IMAP4

   QUOTA extension defined in rfc2087.

   .. versionadded:: 2.3

.. method:: IMAP4.shutdown()

   Close connection established in ``open``. You may override this method.

.. method:: IMAP4.socket()

   Returns socket instance used to connect to server.

.. method:: IMAP4.sort(sort_criteria, charset, search_criterion[, ...])

   The ``sort`` command is a variant of ``search`` with sorting semantics for the

   results.  Returned data contains a space separated list of matching message

   numbers.

   Sort has two arguments before the *search_criterion* argument(s); a

   parenthesized list of *sort_criteria*, and the searching *charset*.  Note that

   unlike ``search``, the searching *charset* argument is mandatory.  There is also

   a ``uid sort`` command which corresponds to ``sort`` the way that ``uid search``

   corresponds to ``search``.  The ``sort`` command first searches the mailbox for

   messages that match the given searching criteria using the charset argument for

   the interpretation of strings in the searching criteria.  It then returns the

   numbers of matching messages.

   This is an ``IMAP4rev1`` extension command.

.. method:: IMAP4.status(mailbox, names)

   Request named status conditions for *mailbox*.

.. method:: IMAP4.store(message_set, command, flag_list)

   Alters flag dispositions for messages in mailbox.  *command* is specified by

   section 6.4.6 of :rfc:`2060` as being one of "FLAGS", "+FLAGS", or "-FLAGS",

   optionally with a suffix of ".SILENT".

   For example, to set the delete flag on all messages::

      typ, data = M.search(None, 'ALL')

      for num in data[0].split():

         M.store(num, '+FLAGS', '\\Deleted')

      M.expunge()

.. method:: IMAP4.subscribe(mailbox)

   Subscribe to new mailbox.

.. method:: IMAP4.thread(threading_algorithm, charset, search_criterion[, ...])

   The ``thread`` command is a variant of ``search`` with threading semantics for

   the results.  Returned data contains a space separated list of thread members.

   Thread members consist of zero or more messages numbers, delimited by spaces,

   indicating successive parent and child.

   Thread has two arguments before the *search_criterion* argument(s); a

   *threading_algorithm*, and the searching *charset*.  Note that unlike

   ``search``, the searching *charset* argument is mandatory.  There is also a

   ``uid thread`` command which corresponds to ``thread`` the way that ``uid

   search`` corresponds to ``search``.  The ``thread`` command first searches the

   mailbox for messages that match the given searching criteria using the charset

   argument for the interpretation of strings in the searching criteria. It then

   returns the matching messages threaded according to the specified threading

   algorithm.

   This is an ``IMAP4rev1`` extension command.

   .. versionadded:: 2.4

.. method:: IMAP4.uid(command, arg[, ...])

   Execute command args with messages identified by UID, rather than message

   number.  Returns response appropriate to command.  At least one argument must be

   supplied; if none are provided, the server will return an error and an exception

   will be raised.

.. method:: IMAP4.unsubscribe(mailbox)

   Unsubscribe from old mailbox.

.. method:: IMAP4.xatom(name[, arg[, ...]])

   Allow simple extension commands notified by server in ``CAPABILITY`` response.

Instances of :class:`IMAP4_SSL` have just one additional method:

.. method:: IMAP4_SSL.ssl()

   Returns SSLObject instance used for the secure connection with the server.

The following attributes are defined on instances of :class:`IMAP4`:

.. attribute:: IMAP4.PROTOCOL_VERSION

   The most recent supported protocol in the ``CAPABILITY`` response from the

   server.

.. attribute:: IMAP4.debug

   Integer value to control debugging output.  The initialize value is taken from

   the module variable ``Debug``.  Values greater than three trace each command.

.. _imap4-example:

IMAP4 Example

-------------

Here is a minimal example (without error checking) that opens a mailbox and

retrieves and prints all messages::

   import getpass, imaplib

   M = imaplib.IMAP4()

   M.login(getpass.getuser(), getpass.getpass())

   M.select()

   typ, data = M.search(None, 'ALL')