This bugs me like crazy, every time i compose an email i have a dropdown with multiple email addresses for each account. Especially the old one which i've had since the days of .mac has @mac.com, @me.com and @icloud.com. My apple id is assigned to the @mac.com address from back then. But i can't just use that one to email. I logged into my apple id on apple's site and deleted the alternatives but they stil pop up in Mail.