mac mail...unable to connect

So, you have your incomming POP Server set to mail.comcast.com or something like that? (Assuming it is Comcast email that you want to get...)

(Next would be your outgoing SMTP Server...)

Comcast should have a help page somewhere online that can tell you what these URLs are...

I have one SMTP Server set for outgoing (smtp.cox.net or mail.cox.net, I'm not home so I can't check) and several incomming servers (like mail.xyz.com). Shouldn't be tooo hard... ;-)

 

That's funny because Mail, in 10.5.6 should be able to automatically configure a comcast account. The fact that you made the switch using migration assistant sounds like it's the problem.

I would suggest making sure your settings are correct as was said.

Choose Mail > Preferences (or press command + comma)

Choose the accounts tab

Under the account information tab, your incoming mail server should be mail.comcast.net your username and password should be the first part of your comcast email address (so minus the @comcast.net) then just enter your password.

Your outgoing server should be smtp.comcast.net

You may also want to create a "TEST" account for your system (in system preferences > users) to test mail on a clean user you didn't do a migration with.