El Capitan Mail.app iCloud email account default email address Just upgraded to El Capitan OS X 10.11 and my default email account is no longer ending with mac.com but is now me.com.

When I try to change this it won't let me save it within the mail.app program.

Any suggestions?
Wow...found an answer elsewhere.  Basically, sign out of iCloud (System Preferences --> iCloud), restart, sign in to iCloud, restart, open Mail.  Everything seemed to reset just fine, and I could save changes to the account in Mail Preferences.