Authorize.net - SMTP Mail Error at Confirmation

[xtremelyfit]

When I click on "Confirm" to finish the credit card processing in my checkout I get the following error message: Can anyone help me?

 

Warning: mail() [function.mail]: SMTP server response: 501 5.5.4 Invalid Address in d:websitesxtremelyfitcomshopcatalogincludesclassesemail.php on line 500

 

Warning: Cannot modify header information - headers already sent by (output started at d:websitesxtremelyfitcomshopcatalogincludesclassesemail.php:500) in d:websitesxtremelyfitcomshopcatalogincludesfunctionsgeneral.php on line 29

[Guest]

http://wiki.oscommerce.com/helpErrors

 

HTH

The_Bear

[xtremelyfit]

Thanks for the url. That doesn't seem to be my problem. I checked all the files out for the trailing spaces. Any other ideas? I'm really at a stand still.