Article ID: 125481, created on May 12, 2015, last review on Feb 17, 2016

  • Applies to:
  • Plesk 12.5 for Linux
  • Plesk 12.0 for Linux


Horde webmail login failed.

Log /var/log/psa-horde/psa-horde.log contains the following error:

    2014-12-07T20:37:33+00:00 WARN: HORDE [imp] [login] Could not open secure TLS connection to the IMAP server. [pid 35439 on line 732 of "/usr/share/psa-horde/imp/lib/Imap.php"]

2014-12-07T20:37:33+00:00 ERR: HORDE [horde] FAILED LOGIN for user@domain.tld (user@domain.tld) [] to horde [pid 35439 on line 216 of "/usr/share/psa-horde/login.php"]

Attempt to log in via CLI produces the following error:

~#  php -r '$user="user@domain.tld";$pass="<PASSWORD>";imap_open( "{}", $user, $pass, OP_DEBUG);'
PHP Warning:  imap_open(): Couldn't open stream {} in Command line code on line 1
PHP Notice:  Unknown: TLS/SSL failure for SSL negotiation failed (errflg=2) in Unknown on line 0

gnutls library is installed on the server.


PHP interoperability issue with GNU TLS library.


Make sure the latest version of GNU TLS library is installed.

As a workaround, change the IMAP configuration in Horde webmail by editing the /usr/share/psa-horde/imp/config/backends.php file:

'secure' => 'tls'
'port' => 143


'secure' => 'ssl'
'port' => 993

Final configuration file should look like:

        // IMAP server
        $servers['imap'] = array(
            // ENABLED by default; will connect to IMAP port on local server
            'disabled' => false,
            'name' => 'IMAP Server',
            'hostspec' => 'localhost',
            'hordeauth' => false,
            'protocol' => 'imap',
            'port' => 993,
            'secure' => 'ssl',

Search Words

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