ASSP
From Fail2ban
ASSP filter for Fail2ban
Save the attached assp.conf file into your /etc/fail2ban/filter.d directory.
Add this section to your /etc/fail2ban/jail.conf file:
[assp] enabled = true port = smtp,ssmtp filter = assp logpath = /var/log/assp/maillog.txt
IMPORTANT: Symlink the logs subdirectory of your ASSP installation as /var/log/assp or change the logpath in your jail configuration to point to ASSP's maillog.txt file.
Don't forget to restart fail2ban.
Check the end of your fail2ban.log whether fail2ban picked up ASSP's log file.