I recently had an issue setting Tbird up to work with GD email. I finally got it set up to allow email to be received. My ISP apparently blocks the ports for GD's SSL. When I set it up to use port 110 on the pop server, email started coming down.
I set up smtpout for port 25 but whenever I try to send mail I get an error message that the mail server sent an incorrect greeting. connect error 10060.
I added 3 email accounts to Tbird - all 3 receive the same error message when attempting to send.