Dovecot no longer delivering LMTP mail or allowing access to Inboxes
I just happened to email myself a reminder from my work account to my home address - it got bounced - strange.
A check of my mail logs were being filled with Postfix errors:
postfix/lmtp[6991]: AB7792880B: to=<xxxxx@xxxxxx>, relay=myserver.mydomain[/var/run/dovecot/lmtp], delay=1197, delays=1197/0.02/0.03/0.03, dsn=4.2.0, status=deferred (host myserver.mydomain[/var/run/dovecot/lmtp] said: 451 4.2.0 <xxxxxx@xxxxxx> Permission denied (in reply to end of DATA command))
It seems there was an update done to openSUSE (patch openSUSE-2016-1249) that affected the Dovecot package.
Once again, BTRFS snapshots saved the day. I spent some time comparing the difference before and after the patch and found that permissions had been changed on the dovecot directory. /var/lib/dovecot previously had 755 and it had changed to 750. Switching the permissions back resulted in everything kicking into life.
A couple of handy commands learnt during this time
List recent patches: zypper search -t patch
View details of a patch: zypper info -t patch openSUSE-2016-1249