Clearing old addresses from Mail's auto-complete list

If you find yourself inadvertently emailing friends or colleagues at the address they quit using years ago, chances are Mail.app's Previous Recipients list is at fault. It's easy enough to clear out the cruft; just go to Mail's Window menu and choose Previous Recipients. Select the addresses you want to get rid of (Cmd-click or shift-click to select more than one) and then click Remove From List. So long, bad addresses!