Forcing the Choice of A Mail Account
I recently posted asking the question of how to force the choice of which account to send e-mail from using Mail.app (Forcing the Choice of A Mail Account). As silence responded to this cry for help, I ended up trying to produce a workaround (credits to AJ for not letting me whinge about this to much and for suggesting I head in this direction). Here is what I ended up with.
Step 1: create a new account in the settings with the name “CHOOSE AN ACCOUNT”. Set the server to localhost, with a simple username and password, which are required. Do this through the preferences screen (CMD-,)
Step 2: change the composing options to always send mail from the account just created.
The combination of these two settings will ensure that you are always forced to choose an account when sending a new e-mail message. This already has been a useful opion, stopping me from accidently using the wrong account (which I must admit I did a couple of times beforehand). When you forget you will see the below popup. The important thing to do with this is to choose the “Edit Message” option, and go and choose an account.
This will produce a working solution, and I've been happy with it, having successfully avoided sending an e-mail from the wrong one of my 4 actively used e-mail accounts.