RBL (Realtime Blackhole List)

I find spamhaus.org's RBL is very good at getting rid of most of my spam. Uncomment in exim's configure file the 4 lines beginning with "deny" and ending "dnslists....")

#--------------------------------------------------------------------------------
# Uncomment the following if you want to check against RBL
#--------------------------------------------------------------------------------
deny message = $sender_host_address is listed at $dnslist_domain
hosts = !+relay_from_hosts
!authenticated = *
dnslists = sbl-xbl.spamhaus.org : bl.spamcop.net : dnsbl.ahbl.org
# / korea.services.net : china.blackholes.us : russia.blackholes.us
#--------------------------------------------------------------------------------

Blocking IPs from smtp service

/usr/exim/reject-hosts.txt

This file is used for locking out email by IP numbers.
You can list individual IP's or a block (one entry per line).
157.238.186.133 (157.238.186.133 only)
157.238.186.0/24 (range of 157.238.186.0 to 157.238.186.255)

—by George Szekely