Exim

Install

# apt install exim4-daemon-light

Configure

TODO

Fail2Ban

The filter for Exim is already included in Debian, we just need to activate it. It will filter people trying to log on your server, trying to make it relay spam, and sending nonsense command.

Create file /etc/fail2ban/jail.d/exim.conf

[exim]
enabled  = true
port     = 25,587
logpath  = %(exim_main_log)s