diff --git a/debian/sendmailanalyzer.conf b/debian/sendmailanalyzer.conf
index fe939c0..434b629 100644
--- a/debian/sendmailanalyzer.conf
+++ b/debian/sendmailanalyzer.conf
@@ -309,3 +309,5 @@ NO_HOST_DOMAIN	0
 # this directive to force sendmailanalyzer to take them as sent.
 NO_QUEUE_EXCLUSION	0
 
+# Custom milter-reject regex detected as spam
+#MILTER_REJECT_REGEX Mailbox not found
diff --git a/sendmailanalyzer b/sendmailanalyzer
index c4808ed..a77d1ad 100755
--- a/sendmailanalyzer
+++ b/sendmailanalyzer
@@ -1606,7 +1606,7 @@ sub parse_sendmail
 				$status =~ s/ \(.*//;
 				#push(@{$TO{$host}{$id}{status}}, &clear_status($status));
 			}
-		} elsif ($status =~ /Spam message rejected/) {
+		} elsif ($status =~ /Spam message rejected/ || ($CONFIG{MILTER_REJECT_REGEX} && $status =~ /$CONFIG{MILTER_REJECT_REGEX}/)) {
 			$SPAM{$host}{$id}{relay} = $relay;
 			$SPAM{$host}{$id}{rule} = 'reject';
 			$SPAM{$host}{$id}{spam} = $status;