I have used my @mac.com E mail address for many years and wish to retain it. Recently, with Mountain Lion, I used my E mail address as the Apple ID to access iCloud. Now I can only access my E mail within iCloud, which is inconvenient, and cannot use the postage stamp icon or send photos by email directly from iPhoto etc.
If I change my Apple ID to something new, will my @mac.com E Mail address work both within iCloud and with the postage stamp as it used to?
What did you upgrade to mt lion from? Was your email setup manually at one point? If it was, remove the account, and then make sure you're signed into the icloud preferences in system preferences and mail is checked off. That will automatically setup your email in the mail.app.
Just make sure your mail shows up properly at icloud.com before removing the account from the mail.app, first.