I had something happen today that is hurting pretty bad, and I can't seem to figure it out. Hopefully you guys can give me some ideas. I have a VPS with godaddy. I have multiple clients on this server. Today the emails starting acting funky, so I created a simple php script to send out an email.

If the email is sent from the server (using php script) to an email address hosted on this server, the recipient does not recieve the email.

If the email is sent from the server (using php script) to an email address outside of the server (yahoo, gmail, msn...) the recipient recieves the email.

If the email is sent from outside the server (outlook express, etc..) using an email address inside the server, to an email address inside the server, I recieve the email. This tells me something is going on with the VPS, but I have no idea where to look.

Any ideas are greatly appreciated!