fail2ban/config/filter.d/exim.conf

# Fail2Ban configuration file
#
# Author: Cyril Jaquier
#
#

[Definition]

# Option:  failregex
# Notes.:  regex to match the password failures messages in the logfile. The
#          host must be matched by a group named "host". The tag "<HOST>" can
#          be used for standard IP/hostname matching and is only an alias for
#          (?:::f{4,6}:)?(?P<host>[\w\-.^_]+)
# Values:  TEXT
#

# From exim source code: ./src/receive.c:add_host_info_for_log
host_info = H=\S+ (\(\S+\) )?\[<HOST>\] (?:I=\[\S+\]:\d+ )?(?:U=\S+ )?(P=e?smtp )?

failregex = ^ %(host_info)ssender verify fail for <\S+>: Unrouteable address\s*$
             ^ \S+ F=(?:<>|\S+@\S+) %(host_info)s(?:temporarily )?rejected by local_scan\(\): .{0,256}$
             ^ login authenticator failed for (\S+ )?\(\S+\) \[<HOST>\]: 535 Incorrect authentication data( \(set_id=.*\)|: \d+ Time\(s\))?\s*$

# Option:  ignoreregex
# Notes.:  regex to ignore. If this regex matches, the line is ignored.
# Values:  TEXT
#
ignoreregex =