[Netfilter] Implement protocol error regex, fulfills #4093

data/Dockerfiles/netfilter/server.py

@@ -100,6 +100,7 @@ def refreshF2bregex():
     f2bregex[6] = '([0-9a-f\.:]+) \"GET \/SOGo\/.* HTTP.+\" 403 .+'
     f2bregex[7] = 'Rspamd UI: Invalid password by ([0-9a-f\.:]+)'
     f2bregex[8] = '-login: Aborted login \(auth failed .+\): user=.+, rip=([0-9a-f\.:]+), lip.+'
+    f2bregex[9] = 'NOQUEUE: reject: RCPT from \[([0-9a-f\.:]+)].+Protocol error.+'
     r.set('F2B_REGEX', json.dumps(f2bregex, ensure_ascii=False))
   else:
     try: