Setup the PHP mail() function on a Ubuntu server

I’ve got a DigitalOcean server running Ubuntu 18 with Apache and PHP 7.2. I wanted to be able to send emails from it using the PHP mail() function and WordPress plugins like GravityForms and such.

After a lot of googling, I stumbled upon the excellent and very easy guide below. Only three steps where required to make it work:

1. sudo apt-get install sendmail
2. sudo sendmailconfig (answer Yes to everything)
3. sudo service apache2 restart

Enable PHP mail() function on Ubuntu