User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.6) Gecko/20091216 Shiretoko/3.5.6 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.1.5) Gecko/20091204 Thunderbird/3.0 When setting up a new email account using the automatic cofiguration, Thunderbird makes an incorrect port choice during mail account setup. If an email server offers both port 465 using ssl in wrapper mode and submission on 587 using start tls, Thunderbird chooses port 465. Using ssl 'wrapper mode' on port 465 has been formally depreciated. If it is available Thunderbird should choose to submit to the smtp server over port 587 using start tls. Reproducible: Always Steps to Reproduce: 1. Tools > Account Settings 2. Account Actions > Add Mail Account 3. Enter details of a server offerring SMTP submission over start tls on port 587 and also ssl wrapper mode on 465 Actual Results: If an email server offers both port 465 using ssl in wrapper mode and submission on 587 using start tls, Thunderbird chooses port 465. Expected Results: If it is available Thunderbird should choose to submit to the smtp server over port 587 using start tls. The mail server in this test was running postfix 2.3.3

I think Postfix is subject to bug bug 525643, but I don't know for sure. Thus, the usually preferred port 587+STARTTLS combination is not chosen as the EHLO to the server produces an error response. Also see bug 538809 comment #10.

Testing with Postfix 2.5.1, it indeed refuses an EHLO without argument in the greeting, thus I'd expect this bug to be resolved with a fix for bug 525643.

There is a contradicting statement from the reporter of bug 538809 though, > Thunderbird when setting up a new mail account will attempt to integorgate the > SMTP server. However it often, at least for me, seem to default to 587/None > when it should have found 587/STARTTLS. with an Exim server, thus I'll leave this bug here "unconfirmed" for now.

The same bug-when I tried to set up I had to edit the port setting to 587 because 465 was selected for TLS/ for no security it went to 25 and the one needed was 487. This however did not allow me to send and I still can't.