Hi, @hazlebury!
Thanks for reaching out!
First of all, I’d like to share the main purpose of the WP Mail SMTP plugin. It is to bridge a connection between your WordPress site and your email mailing service (chosen mailer). Simply put, WP Mail SMTP makes it so your site can send emails efficiently. Without the plugin, WordPress can still send email but it does it in a less reliable way. You may end up with emails going into spam or not arriving at all. With WP Mail SMTP, we connect you to an email service that helps to ensure that does not happen.
However, the WP Mail SMTP plugin does not have the feature to create emails/newsletters, mailing lists, etc.
You’ll need to use third-party plugins to create newsletters and the WP Mail SMTP plugin will help you to send these emails from the website successfully.
Kind regards.