I love what CSF does for blocking most attacks, SSH and SMTPAuth being noteable. But I'm looking for a solution to block spammers after a certain number of attempts, either at the exim or firewall level. I was hoping CSF had something like it built in, but it doesn't look that way, so I was examining alternatives like fail2ban specificly for that purpose. what I'm wondering is if the two will conflict. if CSF and/or fail2ban will step on toes if installed at the same time. If yes, what would be a recommended solution for someone who's already running CSF?