vim /etc/fail2ban/jail.d/mail.conf
[postfix]
enabled = true
port = smtp,465,submission
filter = postfix[mode=aggressive]
logpath = /var/log/mail.log
maxretry = 4
[dovecot]
enabled = true
filter = dovecot[mode=aggressive]
# CUSTOM
[spamassassin]
enabled = true
filter = spamassassin
logpath = /var/log/mail.info
maxretry = 1