Issues with opening Roundcube: Connection closed (UID FETCH finished 60.114 secs ago)

Symptoms

• Roundcube takes a lot of time to access the mailbox.

• The following error can be found in /var/log/plesk-roundcube/errors:

  CONFIG_TEXT: [11-May-2018 03:07:04 UTC] PHP Warning: fgets(): SSL read operation timed out in /usr/share/psa-roundcube/program/lib/Roundcube/rcube_imap_generic.php on line 204

• The following error can be found in /var/log/maillog:

  CONFIG_TEXT: May 11 03:07:04 server dovecot: service=imap, user=jdoe@example.com, ip=[::1]. Connection closed (UID FETCH finished 60.114 secs ago) rcvd=459, sent=61956

• System PHP version is 5.6 or lower:

  # php -v | grep cli
  PHP 5.6.33-0+deb8u1 (cli) (built: Jan 5 2018 15:46:26)

Cause

Insufficient Roundcube performance on older PHP versions.

Resolution

Switch Roundcube to a newer PHP version shipped by Plesk. For example, 7.0:

1. Connect to the server via SSH.

2. Make sure that required PHP handler is installed:

   # plesk bin php_handler --list | grep fast | awk {'print $1'}
   fastcgi
   plesk-php56-fastcgi
   plesk-php70-fastcgi
   plesk-php71-fastcgi
   plesk-php72-fastcgi

   If not, refer to the following article to install additional PHP version - https://support.plesk.com/hc/en-us/articles/115000769793

3. Create a custom template file and redefine PHP handler for Roundcube there:

   # mkdir -p /opt/psa/admin/conf/templates/custom/webmail/
   # cp -p /opt/psa/admin/conf/templates/default/webmail/roundcube.php /opt/psa/admin/conf/templates/custom/webmail/
   # sed -i 's/fastcgi/plesk-php70-fastcgi/g' /opt/psa/admin/conf/templates/custom/webmail/roundcube.php

4. Regenerate web server configuration files:

   # /opt/psa/admin/bin/httpdmng --reconfigure-all