Outlook TLS Issue With 4.5.5

[LMStone]

Running NE on SuSE ES9 with GoDaddy commercial certificate...

After upgrading to 4.5.5 from 4.5.3, Outlook users are no longer able to use TLS on port 25 to send email through the Zimbra server. The Zimbra log shows Outlook drops the connection; Outlook complains the server didn't respond.

These Outlook users can send email if we set up SMTP SSL on port 465, but we'd like not to have to go back to our other Outlook users to make this change.

I saw the port 465 mention in the release notes, but didn't see anything there that would indicate Outlook TLS would be impacted.

Any ideas?

Also, what is the appropriate way to escalate tickets in the Support Portal, please? We have a U2 ticket #00011926 that has had no response for a week since we created it.

Thanks!
Mark