Am 08.02.2016 um 21:01 schrieb Stephen:

There is a permissions issue in dovecot 2.21 in the ~/run directory (mine is /var/run/dovecot) at least in Debian 8.

Files created by dovecot imap:

srw------- 1 root root 0 Feb 3 16:46 imap-hibernate srw------- 1 root root 0 Feb 3 16:46 imap-master

changed to make work:

srw-rw-rw- 1 root root 0 Feb 3 16:46 imap-hibernate srw-rw-rw- 1 root root 0 Feb 3 16:46 imap-master

Errors were reported in /var/log/dovecot.log which we use mainly for fail2ban (it gets huge, but ...)

vpopmail version 5.4.33 with one patch

I don't think this is a Debian issue ... possibly could be a vpopmail issue, but it's probably caused by the fact that imap daemons are running as vpopmail:

vpopmail 30182 9187 0 15:02 ? 00:00:00 dovecot/imap

What purpose does vpopmail serve that dovecot alone does not? Isn't it just an ancient leftover from historic qmail times?

Alexander