Exim_-_Specify_Relay_Recipient

Usefulness

When relaying mail from a centralized point to various domains, you tend to pass a large amount of mail to non-existing recipients. This causes unnecessary bidirectional traffic which can be eliminated by setting up a relay recipient list to verify the recipient at RCPT time. Should the recipient address not be in the list the mail will be reject

Creating A Users List

Create a text file for adding/removing users.

# touch /etc/exim/relay_users

Then add full email addresses, aliases and mailing lists to the file.

Edit exim.conf File

Now edit your exim.conf file accordingly (at the end of acl_check_rcpt)

  accept  domains       = +relay_to_domains
          endpass
          verify        = recipient
          recipients    = /etc/exim/relay_users
          message       = relay not permitted

Im sure there are better ways to do this, which requires less housekeeping. If anybody have any ideas to better this - please let me know. This is my first Howto - so please feel free to comment.