I am running with MSN as my provider and have just recently downloaded Thunderbird to supplant Outlook as the main e-mail program on my computer. I have set up my account per the instructions on the wiki, and have even changed the outgoing server port to 587.
I am still not able to receive or send e-mails. It is a POP e-mail address and has the username mXXXXXXX. The server name is mail.michaellarsonphotography.com (I left this port at 110).
When I check for or try to send e-mails, the program just goes and goes without end.