I'm having a bit of problem receiving, but I think it's my config setting at my DNS service. The first thing I did to be able to send was open port 110 and 25 on my AP router as well as my DSL modem.
These might be able to help you troubleshoot your configuration.
Email/SMTP Test Utility: http://www.zoneedit.com/smtp.html
Mailbox/POP3 Test Utility: http://www.zoneedit.com/pop3.html?ad=smtptest