I'm not sure if it's a problem to begin with, but the situation is that run Postfix as a mail server on my computer. Almost a year ago because of numerous failed login attempts I installed fail2ban. It does its job. But it's kinda strange for my taste. It bans an IP, after a few hours unbans it, then after half an hour bans again etc. etc. Some bots try to log in once every 20 minutes to escape the ban.
The load average of the server seems to be fine. Approx 0,20
So my question is... Does it all fall within something normal or it requires some action on my part? Or a login attempt once in 20 minutes is something so light for the server so it's best to ignore it?