========
Timeouts
========

Dovecot has a lot of timeouts in various components. Most of them have
hardcoded values, because there's normally no need to change them. Here
are some of them listed:

Protocol proxies
----------------

-  Dovecot proxy handles IMAP, POP3 and Submission pre-login timeouts and invalid
   error command handling the same as Dovecot backend. After login the
   proxy will continue proxying until the client or the backend
   disconnects.

-  Connect timeout to backend is governed by :dovecot_core:ref:`login_proxy_timeout` which is
   30 seconds by default. Can be overridden by proxy_timeout passdb extra field.

-  After connection has been established, there's still a login timeout
   ``CLIENT_LOGIN_TIMEOUT_MSECS = MASTER_LOGIN_TIMEOUT_SECS*1000``  = 3 minutes
   (`login-common/client-common.h <https://github.com/dovecot/core/blob/main/src/login-common/client-common.h#L33>`__
   and
   `lib-master/master-interface.h <https://github.com/dovecot/core/blob/main/src/lib-master/master-interface.h#L120>`__)

IMAP
----

-  Before login: ``CLIENT_LOGIN_TIMEOUT_MSECS = MASTER_LOGIN_TIMEOUT_SECS*1000`` = 3 minutes
   (same as proxies)

   -  This may be shorter if all the available connections are in use
      (:ref:`service imap-login { client_limit * process_limit } <service_configuration>`). In that
      case the oldest non-logged in connection is disconnected.

-  After login: ``CLIENT_IDLE_TIMEOUT_MSECS`` = 30 minutes (minimum required
   by :rfc:`2060#section-5.4`)

   -  If IDLE command is started, Dovecot never disconnects. Only if the
      connection is lost there will be a disconnection. A dead
      connection is detected by Dovecot periodically sending "I'm still
      here" notifications to client
      (:dovecot_core:ref:`imap_idle_notify_interval` setting -
      default every 2 minutes).

      -  IMAP clients are supposed to send something before 30 minutes
         are up, but several clients don't do this. Some Outlook
         versions even stop receiving new mails entirely until manual
         intervention if IMAP server disconnects the client.

-  Dovecot also disconnects an IMAP client that sends too many invalid
   commands:

   -  Before login: Disconnect on 3rd invalid command
      (CLIENT_MAX_BAD_COMMANDS in
      `imap-login/imap-login-client.c <https://github.com/dovecot/core/blob/main/src/imap-login/imap-login-client.c#L29>`__)

   -  After login: Disconnect on 20th invalid command
      (CLIENT_MAX_BAD_COMMANDS in
      `imap/imap-common.h <https://github.com/dovecot/core/blob/main/src/imap/imap-common.h#L14>`__)

POP3
----

-  Before login: ``CLIENT_LOGIN_TIMEOUT_MSECS = MASTER_LOGIN_TIMEOUT_SECS*1000`` = 3 minutes
   (same as proxies)

   -  This may be shorter if all the available connections are in use
      (``service pop3-login { client_limit * process_limit }``). In that
      case the oldest non-logged in connection is disconnected.

-  After login: ``CLIENT_IDLE_TIMEOUT_MSECS`` = 10 minutes
   (`pop3/pop3-client.c <https://github.com/dovecot/core/blob/main/src/pop3/pop3-client.c#L34>`__)

-  Dovecot also disconnects an POP3 client that sends too many invalid
   commands:

   -  Before login: Disconnect on 3rd invalid command in v2.2.16+, 11th
      on earlier versions (``CLIENT_MAX_BAD_COMMANDS`` in
      `pop3-login/client.c <https://github.com/dovecot/core/blob/main/src/pop3-login/client.c#L25>`__)

   -  After login: Disconnect on 20th invalid command
      (``CLIENT_MAX_BAD_COMMANDS`` in
      `pop3/pop3-client.c <https://github.com/dovecot/core/blob/main/src/pop3/pop3-client.c#L33>`__)


Submission and LMTP
-------------------
-  Before login: ``CLIENT_LOGIN_TIMEOUT_MSECS = MASTER_LOGIN_TIMEOUT_SECS*1000`` = 3 minutes
   (submission, same as proxies)

   -  This may be shorter if all the available connections are in use
      (``service submission-login { client_limit * process_limit }``). In that
      case the oldest non-logged in connection is disconnected.

-  After login: ``CLIENT_IDLE_TIMEOUT_MSECS`` = 5 minutes for LMTP and 10 minutes for Submission.
   (`lmtp/lmtp-client.c <https://github.com/dovecot/core/blob/main/src/lmtp/lmtp-client.c#L28>`__ and
   `submission/submission-client.c <https://github.com/dovecot/core/blob/main/src/submission/submission-client.c#L43>`__)

-  Dovecot also disconnects an SMTP client that sends too many invalid
   commands:

   -  Before login: Disconnect on 10th invalid command.
      (``CLIENT_MAX_BAD_COMMANDS`` in
      `submission-login/client.c <https://github.com/dovecot/core/blob/main/src/submission-login/client.c#L23>`__)

   -  After login: Disconnect on 20th invalid command
      (``CLIENT_MAX_BAD_COMMANDS`` in
      `submission/submission-client.c <https://github.com/dovecot/core/blob/main/src/submission/submission-client.c#L40>`__)