Are you sure it is not because you are using your own SMTP server?

The "No PTR" problem indicates that you are using an SMTP server that does not have a "pointer record" and for anti-spam purposes relay is being denied.

Try using Sprint's SMTP or create a PTR for the outgoing mail server you are using. All you need to do is create a reverse DNS and make sure it is propogated throughout the net. This problem is quite frequent if you are hosting your own SMTP server (your company uses its own mail server).