How to set reply-to address in Apple Mail

I have two accounts set up in Apple Mail. The second account is for backup purposes and because at times the primary account is unavailable. When that happens, I send from the second account but would like the reply-to address to be that of the primary account. Is there a way to set things up this way in Apple Mail?

Solution 1:

Simple!

With a message composition window open in Apple Mail make the following menu selection:

View > Reply-To Address Field

That works for a message-by-message basis. If you want to apply all the time there's a hack you can do this via Terminal:

defaults write com.apple.mail UserHeaders '{"Reply-To" = "reply-to@address"; }'

More details can be found here.

Solution 2:

If the View Reply-To Address option is checked, the Reply-To Address field will be blank in an email draft. It can then be populated as desired.

However if then left unpopulated - or if the View Reply-To Address option is unchecked - on email send it will automatically be set. The email address used will be that of the default account as specified in Preferences.