diff --git a/config/filter.d/sendmail-auth.conf b/config/filter.d/sendmail-auth.conf
index c15a2e0c..84fcbdda 100644
--- a/config/filter.d/sendmail-auth.conf
+++ b/config/filter.d/sendmail-auth.conf
@@ -8,12 +8,14 @@ before = common.conf
 [Definition]
 
 _daemon = (?:sendmail|sm-(?:mta|acceptingconnections))
+# "\w{14,20}" will give support for IDs from 14 up to 20 characters long
 __prefix_line = %(known/__prefix_line)s(?:\w{14,20}: )?
 addr = (?:IPv6:<IP6>|<IP4>)
 
-# "w{14,20}" will give support for IDs from 14 up to 20 characters long
-failregex = ^%(__prefix_line)s(\S+ )?\[%(addr)s\]( \(may be forged\))?: possible SMTP attack: command=AUTH, count=\d+$
-            ^%(__prefix_line)sAUTH failure \(LOGIN\):(?: [^:]+:)? authentication failure: checkpass failed, user=<F-USER>(?:\S+|.*?)</F-USER>, relay=(?:\S+ )?\[%(addr)s\](?: \(may be forged\))?$
+prefregex = ^<F-MLFID>%(__prefix_line)s</F-MLFID><F-CONTENT>.+</F-CONTENT>$
+
+failregex = ^(\S+ )?\[%(addr)s\]( \(may be forged\))?: possible SMTP attack: command=AUTH, count=\d+$
+            ^AUTH failure \(LOGIN\):(?: [^:]+:)? authentication failure: checkpass failed, user=<F-USER>(?:\S+|.*?)</F-USER>, relay=(?:\S+ )?\[%(addr)s\](?: \(may be forged\))?$
 ignoreregex =
 
 journalmatch = _SYSTEMD_UNIT=sendmail.service