Scott Reilly

This plugin adds a checkbox to the profile page for users which allows them to opt into receiving a notification email whenever a comment is made to the site.
If a comment goes into moderation, only users who have the ability to manage comments on the site will receive the moderation notification email.
By default, all users of the site have the ability to subscribe to notifications about comments. A filter is provided to facilitate use of code to customize the feature’s availability to users.
Note: a “user” is a person with an actual login account for the site. The plugin does not facilitate permitting visitors who do not have an account on the site to be able to subscribe to all comments.
Links: <a href="http://coffee2code.com/wp-plugins/optin-comment-notifications/" rel="nofollow ugc">Plugin Homepage</a> | <a href="https://wordpress.org/plugins/optin-comment-notifications/" rel="ugc">Plugin Directory Page</a> | <a href="https://github.com/coffee2code/optin-comment-notifications/" rel="nofollow ugc">GitHub</a> | <a href="http://coffee2code.com" rel="nofollow ugc">Author Homepage</a>

Optin Comment Notifications

Checkboxes on user profiles to receive emails about new comments. Like it says.

Exactly what you want

Allows users to opt into receiving a notification email whenever a comment is made to the site.

techpraani

andreiserban2

kamalsghholdings

Sided is a polling platform that allows you to easily create and insert polls into your content. Turn poll comments on to generate even more engagement on your site. To activate the Sided plugin, enter your API key on the settings page – you can find this key in the Sided dashboard at sided.co. After activating the plugin, view a full list of all polls on your dashboard. Create new polls from this dashboard, or use the “Create poll” block to add new polls while editing your posts. Use the “Select poll” block to insert existing polls into your posts.
Major features in Sided include:
<ul>
<li>A dashboard for viewing all debates.</li>
<li>A list of all debates with the link, status, published date, and short code displayed.</li>
<li>Create a new debate from the dashboard or the new post page.</li>
<li>While creating, debate preview.</li>
<li>Supports debate short codes for easy embedding in posts.</li>
</ul>
<h3>Third Party</h3>
This plugin loads a javascript from https://cdn.sided.co which sends events data of the plugin to google firebase analytics. More details about can be found here https://firebase.google.com/docs/analytics. Usage policy https://firebase.google.com/policies/analytics

Sided

Use the Sided plugin to create and insert discussion polls into your content.

Optin Comment Notifications vs Sided