I upgraded from 5.0.18 on Christmas day. Upgrade went smoothly except for dropping my commercial cert. I've gotten used to that with major upgrades.
Come Monday morning, when everybody started working, emails started getting deferred with message:
(Names and IPs have been changed, but they are correct)
zimbra postfix/error: 5EB901798D11A: to=<email@example.com>, relay=none, delay=0.3, delays=0.04/0.02/0/0.25, dsn=4.4.1, status=deferred (delivery temporarily suspended: connect to server.domain.tld[10.10.10.10]:7025: Connection refused)
When this happens all mail delivery stalls, and all mails continue to get deferred. Also the web client becomes unresponsive.
It seems to get better with a zmmtactl restart and then flushing the queues, however this requires human interaction, which defies the point of the whole thing...
Any help would be highly appreciated. I opened a ticket with support almost a week ago, and have had extremely little response.
At this point, if I could get back to 5.0.18 that would be fine, but I can't even find any documentation on that.
On top of all of this, my boss has strongly suggested I start pricing out Exchange.
Other performance problems: Accessing free/busy for more than a couple users never returns; Web client frequently announces that server is slow...
ZCS Network 6.0.4
2x quad core Xeon 3.0 GHZ
72 Gigs of RAM