Some users in my LAN are subscribed on different mailing-lists and sometimes
it happens that two users are subscribed on the same mailing-list. Of
course, it produces some unnecessary traffic from the Internet to our
network. How can I write a router so that e-mail from definate hosts (stored
in a plain text file) are redirected to some definate users (this list might
be within the router or taken from the same file with hosts), eg. :
