I am involved with some governmental programs and I have been advised to use different mail accounts for correspondence related to each program.
The problem is that there doesn’t seem to be a quick way to tell Mail to change the “send new messages from” setting. (single keystroke preferable, pop-up might work)
This is a real pain. It is too easy to forget how it is set and I have occasionally sent messages from the wrong account.
I don’t see anything in Automator that would help. I don’t want to invest time messing around with AppleScript. I don’t see a plug-in that would do it.