Jordi Cabot

In the Settings->Discussion page, authors of a post can use the checkbox Email me whenever – Anyone posts a comment.
But this does not send an email as well to the site admins. In blogs where you have a number of guest authors, you may want to be informed about all the new comments so you can respond (if the author is missing) or just participate in the discussion.
As a site admin myself, I was missing many comments. This means plenty of missing opportunities to engage with your audience.
To solve this situation, the plugin adds a new checkbox in the Discussion page. If checked, admins will get an alert email for new comments.

Comment Admin Notifier

Very simple plugin that doesn't try to do many things. But the one it does is very useful: as a website owner you want to make sure you're on top of all the comments in the site even comments to posts you didn't write. 

It does one thing and it does it right

With this plugin, admin users get an email alert every time a new comment is posted on ANY post in the site.

Hidekazu Ishikawa

Vektor,Inc.

DRILL LANCER

Naoki Ohashi

Tomoki Shimomura

Daiki Oshima

sysbird

mimi

kaorock72

chiakikouno

nc30

mthaichi

This is a plugin that extends Gutenberg’s blocks.
[Blocks] 
* Alert 
* Balloon 
* Border Box 
* Button 
* Classic FAQ 
* New FAQ 
* Flow 
* Heading (not recommended) 
* Icon 
* Icon Outer 
* Page Content 
* PR Blocks (not recommended) 
* PR Content (not recommended) 
* Responsive Spacer 
* Staff (not recommended) 
* Page list from ancestor 
* Slider 
* Visual Embed 
* Accordion [ Pro ] 
* Animation [ Pro ] 
* Archive list [ Pro ] 
* Blog Card [ Pro ] 
* Breadcrumb [ Pro ] 
* Button Outer [ Pro ] 
* Card [ Pro ] (not recommended) 
* Category Badge [ Pro ] 
* Child page list [ Pro ] 
* Dynamic Text ( Post Type name / Ancestor Page name ) [ Pro ] 
* Fixed Display [ Pro ] 
* Icon Card [ Pro ] (not recommended) 
* Post list [ Pro ] 
* Post list Slider [ Pro ] 
* New Badge [ Pro ] 
* Selected Post List [ Pro ] 
* Step [ Pro ] 
* Tab [ Pro ] 
* Table of Contents [ Pro ] 
* Taxonomy [ Pro ] 
* Timeline [ Pro ] 
* Grid Column [ Pro ] 
* Grid Column Card [ Pro ] 
* Outer [ Pro ]
[Extensions] 
* Hidden extension 
* Highlighter 
* Inline Font Size 
* Margin extension 
* Nowrap 
* Responsive BR 
* Columns direction 
* Custom CSS [ Pro ] 
* Link toolbar
[ Settings ] 
* Balloon 
* Custom Format [ Pro ] 
* Custom Block Style [ Pro ] 
* Common Margin 
* Load Separate 
* FAQ Block [ Pro ] 
* Custom CSS [ Pro ] 
* Block Manager 
* Block Style Manager
[ Tools ] 
* Import Export
[ Editing and correction ]
The source code of this plugin is below. 
https://github.com/vektor-inc/vk-blocks

Comment Admin Notifier vs VK Blocks