forwarding email messages on iphone4

I have the verizon iphone and have both gmail and aol email accounts supported. I dont have any issues in forwarding email messages off my gmail account, but when I try to forward email messages off my aol account I get the following error message:
Cannot send email. A copy has been placecd in your Outbox. The recipient ...... was rejected by the server because it does not allow relaying.
any input on what this is all about and what the fix is?