ISPconfig Protection / security
I have a server /Ubuntu, 20GB,512MB,300GB B.W/ with ISPconfig installed. All is working well thanks to the forum support. I would like to add extra security to the server noting that I only installed Ubuntu server as per recommendation but now I feel that we might need strong spam protector, an advanced firewall or other security walls.
We noticed that if one of our clients puts a weak password (which we could not put rules to force a better password) then spammers exploit it as fast as a blink of an eye (as we are like listed on a public list of hit them!).
Can anyone suggest like the best fit solution to use with ISPconfig for protection and a method to force users to follow a rule for password setting (like one CAP letter, one number one symbol)