Maillog: Error: net_connect_unix(/var/run/dovecot/stats-writer) failed: Permission denied

Symptoms

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

  CONFIG_TEXT: postfix/pipe[11470]: 0FBA25698AB: to=jdoe@example.com, relay=plesk_virtual, delay=0.17, delays=0.13/0/0/0.03, dsn=2.0.0, status=sent (delivered via plesk_virtual service (lda(jdoe@example.com,)Error: net_connect_unix(/var/run/dovecot/stats-writer) failed: Permission denied))

• There is no custom configuration for Dovecot stats service:

  # grep -r stats /etc/dovecot/
  # << empty output

Cause

This is bug with ID #PPPM-10408 in Dovecot, which will be fixed in Plesk future releases.

Resolution

1. Connect to the server via SSH.

2. Create a file /etc/dovecot/conf.d/25-custom-stats.conf with the content below:

   CONFIG_TEXT: service stats {
   unix_listener stats-reader {
   user = root
   group = popuser
   mode = 0600
   }
   unix_listener stats-writer {
   user = root
   group = popuser
   mode = 0660
   }
   }

   Note: File prefixes between 10 & 20 and 90 to 95 (inclusive) are reserved for Plesk. Please do not use them or edit files with these prefixes.

3. Restart Dovecot service:

   # systemctl restart dovecot