Nikos Roussos

This plugin is relying just on your <code>wp-config.php</code> file. It uses smtp connection details you will set up there to configure WordPress to relay all outgoing emails through that email server.
<h4>Background</h4>
There are plenty of similar type of plugins out there. Most of them are not focused on relaying emails to an SMTP server, but rather supporting specific mail services.
But the main incentive for this was the fact that the <a href="https://hub.docker.com/_/wordpress" rel="nofollow ugc">official WordPress docker image</a> doesn’t have support for sending out emails (eg. “forgot password”).

Config Email SMTP

A simple Wordpress plugin to configure email SMTP preferences using wp-config variables.

rajuru

SparkPost

The <a href="https://www.sparkpost.com/" rel="nofollow ugc">SparkPost</a> email delivery service offers best in class deliverability to ensure your mail hits the inbox, live analytics to review, track and optimize your email activities, as well as highest performance when you need it most: always.
When the SparkPost plugin is enabled, all outgoing email from your WordPress installation is sent through your SparkPost service. From within <a href="https://app.sparkpost.com/" rel="nofollow ugc">the SparkPost UI</a> or <a href="https://app.eu.sparkpost.com/" rel="nofollow ugc">SparkPost EU UI</a>, you can then watch your campaigns unfold live by tracking your engagement metrics, learn what your audience responds to and even integrate more deeply with your app using the SparkPost API.
Requirements 
– PHP 7.0 or later 
– WordPress 5.5 or later

Send all your email from WordPress through SparkPost, the most advanced email delivery service.

Config Email SMTP vs SparkPost