Reader Nathan Atkins provides the opportunity for me to issue an answer comprised entirely of command. He writes:
Do you know how I can remove previous email recipients from my recipients list in the Mail program? I know that if I begin typing in a name and select it, then if I click on the recipient’s name it shows several options, one of which is “remove from previous recipients list.” But, is there a way to see a complete list of previous recipients and edit it from there?
Window -> Previous Recipients
Select All
Remove From List