Closing Open Relay in Exim

To close the open relay run:

/scripts/fixrelayd
/etc/rc.d/init.d/antirelayd restart
service exim restart

If that doesn’t work then

edit /etc/exim.conf, you should see in line 61 (or close if somebody
changed the default configuration) the definition of which hosts are
allowed relaying :

hostlist relay_from_hosts = 127.0.0.1:192.168.10.0/24

These values will allow localhost and few ips.
Nothing else. Adjust the values according to the requirement.

OR

hostlist relay_from_hosts = 127.0.0.1

This will allow only localhost to have open relay.

That’s all you need to do to change to avoid open relay.

For checking whether it is open relayed do use any one of the following links :-

http://www.rbl.jp/svcheck.php

http://www.checkor.com/