We just switched to FiOS and my email client stopped working. Doh! So a quick check with my hosting provider, and they also allow sending email on another port. I updated Thunderbird to send on the alternate port, and email is sending again. Whew. Just thought I would share. There are only a couple options: either your hosting provider for your domain must allow outgoing SMTP on a different port, or you might have to contact FiOS and use their email servers for outgoing email.
Where is the setting? Depends on your email client, but for Thunderbird 3.1, it is under Tools –> Account Settings. Scroll all the way to the bottom where it says “Outgoing Server.” Select your default server and click Edit. In the Port text box, type in the new port number and click OK.
Fun? Of course it is.