Your pop3 and smtp servers are mail.bellsouth.net and I believe that bellsouth requires smtp authentication. Did you try placing a check mark in the SSL authentication box in the treomail set up? I'm not sure if treo mail works with BellSouth, you might also try Eudora as I've read that others are able to send and retrieve bellsouth email with this email client as it supports authentication.
http://palmgear.com/software/showsoftware....64&prodID=12042