I am also having trouble setting up mail in my iMac with Verizon Fios. When I try to send mail I get this message:
cannot send message using server outgoing.verizon.net
The sender address..........was rejected by the server outgoing.verizon.net
Any ideas would be appreciated. I really want to be able to email from iPhotos
Not really sure how everything is setup with gmail but it might be an issue with Apple Mail settings. Check to see if there is an option to leave copies of your emails (messages) on the server.
Apple Mail might be grabbing the email from Verizon and deleting it after it takes it, before Gmail gets the email. If you choose to leave copies on the server, it will just copy the message without deleting it. Dunno if that will solve the issue -- but worth giving a shot.