How to Secure Email Server Against Hacking with VPN (CentOS/RHEL)
In this tutorial, I’m going to share with you my tips and tricks to secure CentOS/RHEL email servers against hacking with a self-hosted VPN server. Many spammers are trying to hack into other people’s email servers. If successful, they would use the hacked email server to send large volumes of spam or steal valuable data. Why do we use a self-hosted VPN server? Because it allows you to enable whitelisting, so only trusted users connected to the VPN server can access your mail server.
Prerequisites
It’s assumed that you have an email server up and running. If not, follow one of the tutorials below to set up your own mail server.
It’s also assumed that you have set up a VPN server. If not, please follow one of the tutorials below. The mail server and VPN server can run on separate hosts, or on the same host.
Read full tutorial here: https://www.linuxbabe.com/redhat/secure-email-server-against-hacking-with-vpn
