I am currently hosting a few domains on a redhat box and everything is running great, except for one puzzling issue. I can't figure out how to allow invalid emails to be delivered to the sender instead of them coming back to me, the postmaster. I am running Sendmail as the mail server. here is an example:
User with email address:
user@userdomain.com
sends a email to an invalid email address like:
invalid@badurl.com
Being that I have the postmaster mail account I get a mail message that come backs to as a undelieverable mail message from the email address:
invalid@mydomain.com
for starters shouldn't it come from "invalid@badurl.com"? Second, how do I allow these messages to go back to the sender instead of the postmaster?