I'd like to get SMTP AUTH working with Zimbra too
We have an external spam appliance as the listed mx, and external mail should go to that, not directly to the mail server. Therefore we'd like anything not in mynetworks to have to authenticate.
On my test server, I got SMTP AUTH working when I test it by telnetting to port 25, but now plaintext imap logins are broken. I get an error from the mail client about how I may need to connect via SSL or TLS.
These are the postfix settings I changed:
I also changed this zimbra setting: zimbraMtaTlsAuthOnly FALSE
This zimbra setting looks ok: zimbraImapCleartextLoginEnabled TRUE