I recently configured cPanel on my VPS. And today I saw the logs in /var/log/messages showing some IP keeps trying to login and failed:
Oct 19 18:10:30 servername dovecot: pop3-login: Aborted login (auth failed, 1 attempts): user=, method=PLAIN, rip=181.28.12.12, lip=xxx.myip.xxx.xxx
I found this because I saw a cPanel alerting email about "imap failed @ Sat Oct 19 17:39:54 2013. A restart was attempted automagically."
this error keeps showing up almost per second base. Oh geez... How to stop this? Any way to prevent this IP from accessing my mail server?
Thanks.