choice of From item when replying

• What happened:

I received an e-mail whose To field is: a@b.c.
I clicked on reply and the From field was: w@x.y.z.

• What could explain that:

I have a rule on a@b.c mailbox that automatically forward e-mails to w@x.y.z
I also receive e-mails at various e-mails based on the pattern *@x.y.z.

• Problem:

In this case, I would prefer my address stays a@b.c for the destinatory. Forwarding to w@x.y.z is my messy cooking :)
However, If I receive an e-mail whose To field is w@x.y.z, I would like the reply to be sent From w@x.y.z.

• What I tried:

I clicked on Edit source to place a@b.c as the first e-mail address, thinking it could give it a kind of priority, but it did not work as I expected.

Do you think MailMate could better handling this case?