Upgrading a mail server from Debian Wheezy (7) to Debian Jessie (8), the following errors were observed in the mail.error log:
dovecot: master: Error: systemd listens on port 143, but it’s not configured in Dovecot. Closing. dovecot: master: Error: systemd listens on port 993, but it’s not configured in Dovecot. Closing
Looking for solutions, I found two pages talking about it:
https://sowhatisthesolution.wordpress.com/2015/04/27/upgrading-dovecot-debian-wheezy-to-jessie/ (local archive)
http://appbead.com/blog/fix-errors-reported-in-syslog-for-debian-8-jessie.html (local archive)
Seeing as this install of dovecot wasn’t supposed to be started by socket connections, but rather run all the time, and that it wasn’t actually listening to POP3 and IMAP, but rather their SSL equivalents, we simply disabled the dovecot.socket config, as suggested by the first of the two links:
# systemctl disable dovecot.socket Removed symlink to /etc/systemd/system/sockets.target.wants/dovecot.socket.