I noticed this perhaps unrelated problem in the log:
Apr 14 14:00:51 mailscan postfix/smtp[73427]: fatal: shared lock
active/29E97222038E_9DE187AF: Resource temporarily unavailable
Let's ignore the non-Postfix queue filename for a moment.
The above error message means that the queue manager has opened a
queue file while some delivery request for that file is still in
progress.
This was not supposed to happen when I originally released Postfix.
To avoid duplicate deliveries after "postfix reload", delivery
agents shared-lock a queue file while processing a delivery request
from the queue manager. The queue manager will not read recipients
from a queue file when it can't get an exclusive lock on that file.
However, both old and new qmgr have code that will proactively read
more recipients from queue file before all in-memory recipients
have been processed. As CPUs get faster, races become more likely,
and the above error will become more likely.
I'll guard the above fatal error so it happens only when
the problem is persistent.
Wietse
