fail2ban/config/filter.d/exim-spam.conf

# Fail2Ban filter for exim the spam rejection messages
#
# Honeypot traps are very useful for fighting spam. You just activate an email
# address on your domain that you do not intend to use at all, and that normal
# people do not risk to try for contacting you. It may be something that 
# spammers often test. You can also hide the address on a web page to be picked
# by spam spiders. Or simply parse your mail logs for an invalid address 
# already being frequently targeted by spammers. Enable the address and 
# redirect it to the blackhole. In Exim's alias file, you would add the 
# following line (assuming the address is honeypot@yourdomain.com):
#
# honeypot:  :blackhole:
#
# For the SA: Action: silently tossed message... to be logged exim's SAdevnull option needs to be used.
#
# To this filter use the jail.local should contain in the right jail:
#
# filter = exim-spam[honeypot=honeypot@yourdomain.com]
#

[INCLUDES]

# Read common prefixes. If any customizations available -- read them from
# exim-common.local
before = exim-common.conf

[Definition]

failregex =  ^%(pid)s \S+ F=(<>|\S+@\S+) %(host_info)srejected by local_scan\(\): .{0,256}$
             ^%(pid)s %(host_info)sF=(<>|[^@]+@\S+) rejected RCPT [^@]+@\S+: .*dnsbl.*\s*$
             ^%(pid)s \S+ %(host_info)sF=(<>|[^@]+@\S+) rejected after DATA: This message contains a virus \(\S+\)\.\s*$
             ^%(pid)s \S+ SA: Action: flagged as Spam but accepted: score=\d+\.\d+ required=\d+\.\d+ \(scanned in \d+/\d+ secs \| Message-Id: \S+\)\. From \S+ \(host=\S+ \[<HOST>\]\) for <honeypot>$
             ^%(pid)s \S+ SA: Action: silently tossed message: score=\d+\.\d+ required=\d+\.\d+ trigger=\d+\.\d+ \(scanned in \d+/\d+ secs \| Message-Id: \S+\)\. From \S+ \(host=(\S+ )?\[<HOST>\]\) for \S+$

ignoreregex = 

[Init]

# Option:  honeypot
# Notes.:  honeypot is an email address that isn't published anywhere that a
#          legitimate email sender would send email too.
# Values:  email address

honeypot = trap@example.com

# DEV Notes:
# The %(host_info) defination contains a <HOST> match
#
# Author: Cyril Jaquier
#         Daniel Black (rewrote with strong regexs)