Mac OS X Lion Mail not sending Since upgrading to Mac OS X Lion, I consistently have issues sending mail from Mail.app. I can receive mail but when I send mail it stays in the outbox. Sometimes I can send the mail in the outbox by deleting it, rebooting my MacBook Pro, and then recreate the message and send it out.

Does anyone have a solution?
These problems usually come down to one of two things:


You have incorrectly configured the log-in settings for your outgoing mail server run by the company that provides your email service. Port numbers, authentication method, user name, password, and other settings.
The problem is on the end of the company that provides your email service. Their servers are misbehaving.


In either case, call the tech support line of the company that provides your email service and have them troubleshoot it with you.