There are many projects that require the ability to send emails, but creating a mail server can also be a project on its own.
So, we will see the different steps of setting up an email server, be it a simple SMTP or a complete suite with webmail.

Postfix is the main service to install on Raspberry Pi to host a mail server. It’ll send and receive emails.
Then other services can be added, like Dovecot for POP/IMAP support and Roundcube can be used as webmail.