I'm trying to help a buddy set up his mail system a bit better. We
have exim4 and MailScanner set up on his primary machine and also
his secondary MX. His primary gladly chunks mail for non-existant
users. However, anything that gets pushed to his secondary just
gets forwarded to the primary, and that can be a lot of crap. The
two systems are virtuallly mirrors, with just the slight config
change for exim on the secondary.
I can't get my mind around this, although I know there has to be a way.
How can I have the secondary validate the recipient and not simply
forward it to the primary for delivery?