I have 3 accounts in Mail, A, B, and C. A - I would never like to send out of A. B - I would only like to send out of B if I am replying to an email to B. C - I always want to send out of C, unless B above. Is there any way to do this? If not, is it possible to always send out of C? There is a "send new messages from" setting in preferences, but that only seems to work for new mail as opposed to replies.