getting filters to use reply-to rather than the originating email address I'm receiving emails that are send to me by one email address (a web server)- which I don't want -  and have a reply-to field set to a users email- that I do want.

I'd like to auto reply to these emails so the users' know I have received them, but the filter is sending the reply back to the originator (which is a no-reply address) and not using the reply-to field address, whee I'd like it to go.

Does anyone know how to force Mac Mail to use the reply-to field when replying to a message?
You could use the 

Rules in Mail and

When message arrives from ??

Forward to: someones.email.com

with predefined and automated message text that you write only once.