I have been having the same problem as on thread
Internal Mails Stop Working After a While
This is where mail gets stuck in the mail queue.
If the following is done
This almost always flushes the queue.
However this is not neat and I want a better work around until the other thread has identified the core problem.
I have used M1 and it was OK and I made the mistake of going live with M2
so I am manually running the process above every 30 minutes.
I would much rather
1) Stop postfix
2) Start postfix
3) Flush the queue
Then automate this in a cron job.
How do we stop and start postfix in the zimbra environment, do we need to be logged in as zimbra or root?
I know this is not the solution to the problem, but all hell breaks loose when I
forget to not run the manual flush.