undelivered mail return

[vs_isp]

It seems that it has to do with the fact that the receiver address in the contact form script is a google apps address. The receiver address has the same domain with the site but i haven't configured any email accounts under ispcp, only under google apps. When i use a different address not in the same domain it sends the mail with no errors...
Also the mail.log has no errors since the 4th of march...
The contact form is not a part of a cms.