Ok I can't quite figure out what the problem is with why I can't send emails.
If I do a test email through the email account setup it goes through fine.
When I send an email this is the error message that comes up.

Your message did not reach some or all of the intended recipients.

Subject: test email
Sent: 2/3/2007 3:57 PM

The following recipient(s) could not be reached:

' on 2/3/2007 3:57 PM
553 Sorry, that domain isn't in my list of allowed rcpthosts.

It does this no matter what email address I send a message to. I can
receive email to this address but I can't send it. Any suggestions on how to
fix this? I have never seen it before. Does it have something to do with my
firewall maybe?