Webmail login issue: Roundcube Connection to storage server failed

Created:

2016-11-16 13:19:33 UTC

Modified:

2017-04-24 11:03:56 UTC

2

Was this article helpful?


Have more questions?

Submit a request

Webmail login issue: Roundcube Connection to storage server failed

Applicable to:

  • Plesk 12.5 for Linux
  • Plesk Onyx for Linux
  • Plesk 11.5 for Linux
  • Plesk 12.0 for Linux
  • Plesk 12.5 for Windows

Symptoms

Sometimes, hosting clients cannot log in to Roundcube or using anther IMAP client on Dovecot IMAP server. Valid credentials are used. The following error appears:

Roundcube Connection to storage server failed

In the ' /var/log/maillog ' the following error message can be found:

dovecot: master: Warning: service(imap-login): process_limit (100) reached, client connections are being dropped
...
...
dovecot: service=lda, user=user@example.com, ip=[]. Error: userdb lookup: connect(/var/run/dovecot/auth-userdb) failed: Connection refused
dovecot: lda: Fatal: Internal error occurred. Refer to server log for more information.
postfix/pipe[185750]: E57D84520062: to=<user@example.com>, relay=plesk_virtual, delay=1.7, delays=0.66/0/0/1.1, dsn=4.2.1, status=deferred (Message can not be delivered at this time )

The following errors appear in /var/log/plesk-roundcube/errors log:

[10-Nov-2016 09:16:47 +0100]: <4gtu8jeh> IMAP Error: Login failed for kru@example.com from 203.0.113.4(X-Real-IP: 203.0.113.2). Empty startup greeting (localhost:143) in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap.php on line 193 (GET /?_task=mail&_action=search&_filter=ALL&_interval=&_q=ik&_headers=subject%2Cfrom&_scope=base&_mbox=INBOX&_remote=1&_unlock=loading1478765408628&_=1478765335293)

Cause

Dovecot connections limits exhausted

Resolution

  1. Create a file /etc/dovecot/conf.d/99-imap-login.conf with the following content:

    service imap-login {
    process_limit = 200
    process_min_avail = 16
    }
  2. Tune process_limit value according to the server load.

Have more questions? Submit a request
Please sign in to leave a comment.