diff --git a/config/filter.d/postfix.conf b/config/filter.d/postfix.conf
index 8db7faee..d2dc4a0c 100644
--- a/config/filter.d/postfix.conf
+++ b/config/filter.d/postfix.conf
@@ -15,6 +15,7 @@
 # Values:  TEXT
 #
 failregex = reject: RCPT from (.*)\[<HOST>\]: 554
+            reject: RCPT from (.*)\[<HOST>\]: 450 4\.7\.1 : Helo command rejected: Host not found; from=<> to=<> proto=ESMTP helo= *$
 
 # Option:  ignoreregex
 # Notes.:  regex to ignore. If this regex matches, the line is ignored.
diff --git a/testcases/files/logs/postfix b/testcases/files/logs/postfix
new file mode 100644
index 00000000..28ff95a4
--- /dev/null
+++ b/testcases/files/logs/postfix
@@ -0,0 +1,3 @@
+# per https://github.com/fail2ban/fail2ban/issues/125
+# and https://github.com/fail2ban/fail2ban/issues/126
+Feb 21 09:21:54 xxx postfix/smtpd[14398]: NOQUEUE: reject: RCPT from example.com[192.0.43.10]: 450 4.7.1 : Helo command rejected: Host not found; from=<> to=<> proto=ESMTP helo=