Connection between postfix and dovecot failing

[Angus Fox]

On 28 Nov 2015, at 17:14, Sytse Kuijk <sytse at pobox.com> wrote:

>I am running a Mac mini with OSX server version 10.5, that is on El Capitan, but the problem I have started on Yosemite (the previous version) and did not change at all in the upgrade (I had hoped it would have solved itself). … Since we suffered a short power outage a little over a week ago, the mail has failed in delivering messages to the local mailboxes. 

So it sounds like you ran an upgrade from Mac OS X 10.10.x and OS X Server 5.x or 4.x to Mac OS X 10.11.1 and OS X Server 5.0.15 in order to fix a problem caused by a power outage. I would suggest reverting to a backup from immediately before the power outage and getting it working first before trying to run the upgrade (and the migration it runs) - I have had OS X Server become unrecoverable before due to a power failure and had to rebuild from scratch. Upgrading could not fix the underlying problems with the state that the filesystem was in because there had been a data loss. This was a very painful experience.

Sorry this isn’t specifically Dovecot related, although I have been running Dovecot for years now on a live Mac OS X computer and upgraded to OS X Server 5.0.15 recently with very few issues other than the usual Apple simplification complexities and the fact that the OS X Server installer took a *very* long time to do the migration.

Angus