what can i do about the following, its hitting my both my mail servers repeatedly through each day
May 22 15:30:29 server1 postfix/smtpd: too many errors after AUTH from unknown[126.96.36.199]
May 22 15:30:29 server1 postfix/smtpd: disconnect from unknown[188.8.131.52] ehlo=1 auth=0/1 rset=1 commands=2/3
the last number in ipaddress regularly changes ie 7, 13,14,15 etc
fail2ban is catching it but is there another way to prevent it even hitting my server?
what is the easiest way to block this?