Evolution Doesn't Send mail

[Zach Taylor]

Hey Guys,

I just got Ubuntu installed and it is cool :)

Just one problem, though, Evolution won't send mail. I have it set up correctly -- the same as other boxes on my home network. It just gives this error:  RCPT TO <email at domain> failed: Requested action not taken: mailbox unavailable.

I've talked to the support desk at Earthlink with no results. They say their server is working.

Does Ubuntu include a firewall? Or is there a reason that Evolution cannot communicate through port 25?

TIA

Zach T