Quoth Ian Baker (23 Aug 2014, 18:17):
I've just taken over support for an OS X Server (v10.6.8) box, and am a bit new at Postfix & Dovecot.
[...]
And here is what a bounce looks like
Aug 22 07:29:28 mail postfix/local[93916]: error: od[getpwnam_ext]: No record for user sblondin Aug 22 07:29:28 mail postfix/pipe[93944]: 852C43AE7ACC: to=sblondin@eem.ca, relay=dovecot, delay=15, delays=0.14/0.05/0/15, dsn=5.1.1, status=bounced (user unknown)
This looks familiar to me.
I've seen this happen when running Snow Leopard server as well, and recall tracing this back to Time Machine.
IIRC, Time Machine suspends directory services briefly while running.
My wild guess is that this is probably by design, in order to create
consistent database snapshots. And since Time Machine runs quite often
(in its default configuration), that doesn't do much good to services
relying on permanent availability of AAA services.
If you're running Time Machine, try disabling it. You can alter its schedule by hand, or you can use utilities like http://www.klieme.com/TimeMachineScheduler.html to coax it into a a more suitable (less disruptive) schedule.
Regards, Jeroen.
Jeroen Scheerder ON2IT B.V. Regterweistraat 7 4181 CE WAARDENBURG T: +31 88 22 66 200 | F: +31 88 22 66 299 W: www.on2it.net | E: Jeroen.Scheerder@on2it.net