diff --git a/ChangeLog b/ChangeLog
index b63552af..5b2fcfaa 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -65,6 +65,8 @@ ver. 0.10.3-dev-1 (20??/??/??) - development edition
 * `filter.d/asterisk.conf`: fixed failregex prefix by log over remote syslog server (gh-2060);
 * `filter.d/exim.conf`: failregex extended - SMTP call dropped: too many syntax or protocol errors (gh-2048);
 * `filter.d/recidive.conf`: fixed if logging into systemd-journal (SYSLOG) with daemon name in prefix, gh-2069;
+* `filter.d/sendmail-auth.conf`, `filter.d/sendmail-reject.conf` :
+  - fixed failregex, sendmail uses prefix 'IPv6:' logging of IPv6 addresses (gh-2064);
 * `filter.d/sshd.conf`:
   - failregex got an optional space in order to match new log-format (see gh-2061);
   - fixed ddos-mode regex to match refactored message (some versions can contain port now, see gh-2062);
diff --git a/config/filter.d/sendmail-auth.conf b/config/filter.d/sendmail-auth.conf
index 35bf2357..a370eea2 100644
--- a/config/filter.d/sendmail-auth.conf
+++ b/config/filter.d/sendmail-auth.conf
@@ -9,7 +9,7 @@ before = common.conf
 
 _daemon = (?:sendmail|sm-(?:mta|acceptingconnections))
 
-failregex = ^%(__prefix_line)s\w{14}: (\S+ )?\[<HOST>\]( \(may be forged\))?: possible SMTP attack: command=AUTH, count=\d+$
+failregex = ^%(__prefix_line)s\w{14}: (\S+ )?\[(?:IPv6:<IP6>|<IP4>)\]( \(may be forged\))?: possible SMTP attack: command=AUTH, count=\d+$
 
 ignoreregex =
 
diff --git a/config/filter.d/sendmail-reject.conf b/config/filter.d/sendmail-reject.conf
index bdc1c2c1..985eac8b 100644
--- a/config/filter.d/sendmail-reject.conf
+++ b/config/filter.d/sendmail-reject.conf
@@ -23,16 +23,16 @@ _daemon = (?:(sm-(mta|acceptingconnections)|sendmail))
 
 prefregex = ^<F-MLFID>%(__prefix_line)s(?:\w{14}: )?</F-MLFID><F-CONTENT>.+</F-CONTENT>$
 
-cmnfailre = ^ruleset=check_rcpt, arg1=(?P<email><\S+@\S+>), relay=(\S+ )?\[<HOST>\](?: \(may be forged\))?, reject=(550 5\.7\.1 (?P=email)\.\.\. Relaying denied\. (IP name possibly forged \[(\d+\.){3}\d+\]|Proper authentication required\.|IP name lookup failed \[(\d+\.){3}\d+\])|553 5\.1\.8 (?P=email)\.\.\. Domain of sender address \S+ does not exist|550 5\.[71]\.1 (?P=email)\.\.\. (Rejected: .*|User unknown))$
-            ^ruleset=check_relay, arg1=(?P<dom>\S+), arg2=<HOST>, relay=((?P=dom) )?\[(\d+\.){3}\d+\](?: \(may be forged\))?, reject=421 4\.3\.2 (Connection rate limit exceeded\.|Too many open connections\.)$
-            ^rejecting commands from (\S* )?\[<HOST>\] due to pre-greeting traffic after \d+ seconds$
-            ^(?:\S+ )?\[<HOST>\]: (?:(?i)expn|vrfy) \S+ \[rejected\]$
+cmnfailre = ^ruleset=check_rcpt, arg1=(?P<email><\S+@\S+>), relay=(\S+ )?\[(?:IPv6:<IP6>|<IP4>)\](?: \(may be forged\))?, reject=(550 5\.7\.1 (?P=email)\.\.\. Relaying denied\. (IP name possibly forged \[(\d+\.){3}\d+\]|Proper authentication required\.|IP name lookup failed \[(\d+\.){3}\d+\])|553 5\.1\.8 (?P=email)\.\.\. Domain of sender address \S+ does not exist|550 5\.[71]\.1 (?P=email)\.\.\. (Rejected: .*|User unknown))$
+            ^ruleset=check_relay, arg1=(?P<dom>\S+), arg2=(?:IPv6:<IP6>|<IP4>), relay=((?P=dom) )?\[(\d+\.){3}\d+\](?: \(may be forged\))?, reject=421 4\.3\.2 (Connection rate limit exceeded\.|Too many open connections\.)$
+            ^rejecting commands from (\S* )?\[(?:IPv6:<IP6>|<IP4>)\] due to pre-greeting traffic after \d+ seconds$
+            ^(?:\S+ )?\[(?:IPv6:<IP6>|<IP4>)\]: (?:(?i)expn|vrfy) \S+ \[rejected\]$
             ^<[^@]+@[^>]+>\.\.\. No such user here$
-            ^<F-NOFAIL>from=<[^@]+@[^>]+></F-NOFAIL>, size=\d+, class=\d+, nrcpts=\d+, bodytype=\w+, proto=E?SMTP, daemon=MTA, relay=\S+ \[<HOST>\]$
+            ^<F-NOFAIL>from=<[^@]+@[^>]+></F-NOFAIL>, size=\d+, class=\d+, nrcpts=\d+, bodytype=\w+, proto=E?SMTP, daemon=MTA, relay=\S+ \[(?:IPv6:<IP6>|<IP4>)\]$
 
 mdre-normal =
 
-mdre-extra = ^(?:\S+ )?\[<HOST>\](?: \(may be forged\))? did not issue (?:[A-Z]{4}[/ ]?)+during connection to M(?:TA|SP)(?:-\w+)?$
+mdre-extra = ^(?:\S+ )?\[(?:IPv6:<IP6>|<IP4>)\](?: \(may be forged\))? did not issue (?:[A-Z]{4}[/ ]?)+during connection to M(?:TA|SP)(?:-\w+)?$
 
 mdre-aggressive = %(mdre-extra)s