Troubleshooting Thunderbird

I've had it with the "upgrade" to the Web-based email I use at Comcast. (I might be revealing too much about how I get my email, but if you wanted to hack me before there was enough info out there to do it already. I'm assuming you have no interest in accessing my mail at this point.) I used to use Comcast's Web-based email system because I constantly rebuilt machines and liked keeping non-work email elsewhere. Now that I've decided Comcast's "new improved" Web-based system is horrible, I looked for a lightweight mail client and found Mozilla Thunderbird:

When choosing a mail client I wanted one that avoided proprietary formats, like those used by Outlook and Outlook Express. Mozilla/Netscape has had a history of keeping mail files in plain text format, which makes importation and manipulation easy. I also like Thunderbird because it supports SSL enabled POP and SMTP, which according to Comcast they support too. SSL-enabled POP works fine, but this is as far as I get with SSL-enabled SMTP:

21:59:52.049456 IP 192.168.2.4.4067 > 216.148.227.125.465: 
S 1728039870:1728039870(0) win 16384  (DF)
21:59:52.133043 IP 216.148.227.125.465 > 192.168.2.4.4067: 
S 640665924:640665924(0) ack 1728039871 win 65520  (DF)
21:59:52.133152 IP 192.168.2.4.4067 > 216.148.227.125.465: 
. ack 1 win 17640 (DF)

As you can see I can complete a three way handshake, but there the process hangs. I posted this to the support forums (reg required) and to their feedback form. I can't wait to see the replies. Update: I received an email stating this could be a problem with Thunderbird.