It was set at Port 25. I changed it to 587, and this was the error message when I tested it with a hotmail account of mine:
The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'email@example.com'. Subject 'TEST', Account: 'Castlefootball.com', Server: 'mail.castlefootball.com', Protocol: SMTP, Server Response: '554 firstname.lastname@example.org: Relay access denied', Port: 587, Secure(SSL): No, Server Error: 554, Error Number: 0x800CCC79"
Any ideas what I might be doing wrong?