I have two email accounts I use with my mail. I have my Gmail college account and my Outlook College account. I am using OS X 10.8.2 Mountain Lion.
Here is the Screenshot of what pops up when I try to send the mail:
I have tried looking through the options and taking them both offline and bringing them back. I have even deleted both accounts and created them again. I've checked the numbers from the information on the email pages and I'm just incredibly frusturated because I need to communicate with my schools and professors.
MacBook Pro (13-inch, Mid 2012), OS X Mountain Lion (10.8.2)