[SOLVED] Authenticate SMTP with Active Directory

[mmorse]

EDIT: Just saw your addition: "I'll post the result of zmprov gacf, and zmlocalconfig in a while."
and your /etc/hosts lines

[phoenix]

I don't think the problem lies with Postfix because this problem does not occur if I use Thunderbird to send e-mail so it must be the Zimbra Web Mail client. Maybe the Web Mail client is not authenticating properly, is there way to trace this procedure?

This is not a problem with the Zimbra Web UI, it's your configuration of postfix that's the problem. Check the mynetworks configuration, that's what's causing your problem. Don't change any of the ports that Zimbra uses unless you know what you're doing and what you're trying to achieve.

[pornsakb]

Got it. Thanks you all.

[mmorse]

All good?
-hence why it would have been easier to post your config (zmprov gacf, zmlocalconfig, main.cf, hostsfile etc) earlier...it's like unraveling a thread to get to the source otherwise

[pornsakb]

Yes, all is okay now. Thanks for your help.