TecAdmin published a tutorial about installing Postfix on Ubuntu 20.04.
How to Install and Configure Postfix on Ubuntu 20.04
Postfix is a popular Mail transfer agent(MTA) which is a part of SMTP whose full form is Simple Mail transfer protocol and Postfix function is to transfer/send mails from one server to another. Postfix is known because of its determination of routes and sending emails; it is completely free and installable on all major Unix
