Timothy Jacobs

WP Mail Debugger captures and displays all emails sent through wp_mail() for debugging and troubleshooting. A new admin menu, WP Mail Debugger, is added under the Tools menu.
Get the <a href="https://apps.apple.com/us/app/wp-mail-debugger/id1547093438?mt=12" rel="nofollow ugc">Mac App</a> to connect to multiple WordPress websites from one convenient location.

WP Mail Debugger

I "found" this plugin when its creator presented it at WCPhx 2020. Its extremely easy to use, and is helpful in a day and age when SPFF and DKIM issues make debugging mail tough. Show your users the mail is going out. Or as a plugin developer, use it to review output.

This is so good

WP Mail Debugger captures and displays all emails sent through wp_mail() for debugging and troubleshooting.

meloniq

Virtual Mailbox – Log All Outgoing Emails and Browse Them.
<ul>
<li>Logs outgoing emails and assigns them to users.</li>
<li>Automatically prunes older emails.</li>
<li>Includes a shortcode for easily adding the mailbox to the frontend.</li>
<li>Users can view emails that were sent to them in the mailbox.</li>
</ul>

Virtual Mailbox

Virtual Mailbox - log all outgoing emails, and allow to browse them.

WP Mail Debugger vs Virtual Mailbox