I have an auto-responder account set up to send a response back to every
one sending email to the account.  About 5%-10% of the auto-responses
get rejected for invalid email address, or domain name not found.

this is the statement we have in the list header
Reply-to= List,Ignore

Is there a way to make the list look first at a specified "Reply to"
address, and if nothing there than default to the sending email account?