How to remove an autocomplete email address from Apple's Mail app - O'Reilly Answers
Wow, I can’t believe that Apple does this…
Not only does Address Book.app kind of suck, but then they break their own rules by using a separate, basically invisible feature in Mail.app, and make it the preferred location for addresses even when the person exists in your actual Address Book.
Anyway, if you, like me, have to C-n down to your wife’s actual address past the hasn’t-been-used-for-5-years .mac address (yes, dot-mac), you’ll find the instructions here helpful.
