fail2ban/config/filter.d/cyrus-imap.conf

# Fail2Ban configuration file
#
# Author: Jan Wagner <waja@cyconet.org>
#
#

[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
#
failregex = : badlogin: .*\[<HOST>\] plaintext .*SASL\(-13\): authentication failure: checkpass failed$
	    : badlogin: .*\[<HOST>\] LOGIN \[SASL\(-13\): authentication failure: checkpass failed\]$
	    : badlogin: .*\[<HOST>\] (?:CRAM-MD5|NTLM) \[SASL\(-13\): authentication failure: incorrect (?:digest|NTLM) response\]$
	    : badlogin: .*\[<HOST>\] DIGEST-MD5 \[SASL\(-13\): authentication failure: client response doesn't match what we generated\]$

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