Roy Tanck

<h4>Redirect all email sent by WordPress to the admin’s email address.</h4>
When activated, this plugin will send all email sent by WordPress to the admin email address instead of the intended recipient.
It uses the wp_mail filter to modify the “to” address for all email sent by WordPress. When active, all email sent through WordPress’s wp_mail() function is rerouted to the admin email address as configured under “Settings – General”.
One of its uses is to allow the creation of new users during testing. WordPress requires user email addresses to be unique, and sends confirmation messages to these addresses. Using this plugin, you can use fake addresses, and still receive the activation links.

Mail Caesar!

I love plugins which you install and just use without the hassle to go through a bunch of confusing options and settings. This plugin is such a lean and clean little helper, eg. if you need to test functionality for a new website and don't want the mail to be sent to your client.

Bonus for the superb plugin name! 👍🏻

Cool stuff

Redirect all email sent by WordPress to the admin's email address.

Mikael Korpela

Miguel Lezama

A tool to observe how a page loads in different themes simultaneously. 
Useful for debugging plugins or Gutenberg blocks.
How to Use:
<ol>
<li>Install several themes you’d like to check out.</li>
<li>Create a new page.</li>
<li>Navigate to Tools → Back To The Theme</li>
<li>Choose if you want to demo editor- or view side.</li>
<li>Select the themes you’d like to check out.</li>
<li>Choose the page you just created. This page will be previewed with all the themes you’ve selected.</li>
<li>Click Do it!.</li>
<li>Scroll to see the page rendered with all the themes you selected.</li>
</ol>
You’ll see your page load with different themes in a bunch of iframes for handy preview and debugging.
A nice list of popular themes to test:
<pre><code>`
</code></pre>
wp theme install \ 
 astra \ 
 colormag \ 
 customizr \ 
 generatepress \ 
 hestia \ 
 hueman \ 
 oceanwp \ 
 shapely \ 
 storefront \ 
 sydney \ 
 twentyeleven \ 
 twentyfifteen \ 
 twentyfourteen \ 
 twentynineteen \ 
 twentyseventeen \ 
 twentysixteen \ 
 twentyten \ 
 twentythirteen \ 
 twentytwelve \ 
 vantage 
 `
See docs for <a href="https://developer.wordpress.org/cli/commands/theme/install/" rel="nofollow ugc">wp theme install</a>.
<a href="https://github.com/simison/back-to-the-theme" rel="nofollow ugc">Plugin’s source code on GitHub</a>.

Back To The Theme

See a page with different themes all at once, just like that!

Mail Caesar! vs Back To The Theme