Secure Courier-IMAP POP3/IMAP (Plesk) against brute forcing

This article outlines the process of configuring Fail2Ban to secure a Plesk server running Courier-IMAP as its IMAP and POP3 server against brute forcing.

Prerequisite: This article expects that you have already completed the installation of Fail2Ban as outlined here.

Once you have completed the installation of Fail2Ban –

1. Edit /etc/fail2ban/filter.d/courierlogin.conf using nano.

nano -w /etc/fail2ban/filter.d/courierlogin.conf

And change: “LOGIN FAILED, .*, ip=\[< HOST >\]$”

To: “LOGIN FAILED, ip=\[< HOST >\]$”

2. Add the following configuration to /etc/fail2ban/jail.conf: Continue reading “Secure Courier-IMAP POP3/IMAP (Plesk) against brute forcing”