Abhishek Kumar

This plugin allows you to send html new user notification emails in WordPress.
It provides wp editor to edit your email template.
You can also upload images to your mail content.
You can change sender’s name and email.
This plugin was created by Abhishek Kumar http://github.com/abhishekfdd

Html New User Notification

This plugin gives you option for sending html new user notification email.

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.

Html New User Notification vs WP Mail Debugger