Situation: I receive an email from "firstname@mail.com" and I click 'reply' "firstname@mail.com" has a user with a preferred email address: "first-last@domain.com" Question: How do I get the 'To:' field of the reply to auto-populate with "first-last@domain.com" instead of "firstname@mail.com"? Explanation: I am looking for a way to transform the recipient e-mail address that is auto populated in the "To:" field when I click reply. Ideally, I would manually enter the new recipient information only once and Thunderbird would remember and do the transformation every time thereafter. Sort of like a custom auto-correct. So if Thunderbird sees "firstname@mail.com", it 'auto-corrects' it to "first-last@domain.com" Any ideas?