I am having some trouble on my pop account using Mail on my Mac. I can recieve mail but cannot send it. I don't really know what information to give so that people can help, but when i try and send it says ' This message could not be delivered and will remain in your Outbox until it can be delivered. Verify that you have addressed this message correctly. Check your SMTP server settings in Mail Preferences and verify any advanced settings with your system administrator. ' I am using outgoing mail server port 587. Thanks a lot.