I contacted godaddy support before starting this thread, this was their response:
Dear Sir/Madam,
Thank you for contacting Hosting Support regarding your wireworks.net account. We have investigated the issue of your contact form returning errors. I have confirmed php mail() is functioning correctly from your hosting account with test scripts. If you continue to receive this error please review the URL provided by the URL and contact the provider of the Plug-In sending the email for further assistance.
http://pobox.com/~djb/docs/smtplf.html
Please let us know if we can help you in any other way.