Exim

Install
Note: The heavy version is needed to use Dovecot as an authentication mechanism.

Base
Create file

Create folder
Unlike other programs, Exim doesn't read it's certificate as the root user. So it will be unable to read them from the standard let’sencrypt folder. We will create a folder readable by Exim where we can safely drop certificates later

Get certificate

 * 1) Edit file   an add a   line for
 * 2) Activate your new domain in Nginx
 * 3) Edit file   and add the following to the config list
 * 4) Get Your certificate

Use Certificate
Edit  and add the following lines

Authentication
We will use dovecot to verify user login and password. It lets us have only one database of users and share it between the different email infrastructure parts (smtp, imap...)

Dovecot
First modify the file. Find the section  and add the following lines And apply config with

Exim
Create file

Smart catch
This is my #1 spam fighting technique. It allows me to have an infinite number of email addresses while still preventing spammers to generate them.

You can check the installation instructions.

Dovecot Delivery
Create file  Then create

DKIM
Exim/DKIM

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