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Create groups to organize your subscribed users and send them e-mails based on their groups or by user levels, capabilities or usernames. You can also send messages for anybody, directly by e-mail addresses. Besides that, you can use some information of the current user and of a selected publication (post or page), to personalize the message, that can take attached files, if you want. WPMailing offers support if you are using Xinha4WP or Dean’s FCKEditor, to write e-mails in your favorite editor.
<h3>Features</h3>
Once the plugin is activated, your administration panels will offer:
<ul>
<li>The ability to create groups and tag your users, by adding new features in Users section pages 
through Javascript (user.php, profile.php and user-edit.php). 
** This actions will not modify the WP original files.</li>
<li>An interface to modify names and descriptions of your groups (Manage > Groups) </li>
<li>An interface to compose and send e-mails to subscribed users, 
with some interesting features (Write > Write e-mail): 
** The ‘To’ field supports multiple e-mails and inclusions by user level, capability, group or username. 
** You can attach multiple files to the message 
** You can use values of an specific post or page 
** The e-mail can be personalized with informations of the user that will receive the message</li>
<li>An interface to set or update some WPMailing configurations (Options > Mailing) </li>
<li>Complete information about the sending process after you send any e-mail</li>
</ul>
<h3>Feedback</h3>
Your feedback are welcome. 
 Send any bug detections, suggestions, critics, etc. to: wpmailing(at)jsbrasil(dot)com 
 Thank you, Cau Guanabara.

WPMailing

Create groups to organize your subscribed users and send them e-mails based on their groups or by user levels, capabilities or usernames.

Christian Wach

Commentpress

CommentPress Core is an open source theme and plugin for WordPress that allows readers to comment in the margins of a text. Readers may comment paragraph-by-paragraph, line-by-line, block-by-block or by selecting text (coming soon to touch devices).
Annotate, gloss, workshop, debate: with CommentPress Core you can do all of these things on a finer-grained level, turning a document into a conversation. It can be applied to a fixed document (paper/essay/book etc.) or to a running blog. Use it in combination with BuddyPress and Groupblogs to create communities around your documents.
Please note: for the time-being, this plugin works best when the Gutenberg editor is disabled. If you want the simplest CommentPress experience in WordPress 5.x please install the Classic Editor or Gutenberg Ramp plugin to manage the post types on which the Gutenberg editor is enabled.
Please note: this plugin comes bundled with three official themes, one of which must be active for CommentPress Core to function. The “CommentPress Modern Theme” will be auto-activated when the plugin is first activated. The old “CommentPress Default Theme” is still included for those who wish to stay with it or have built their own child themes for it. Since version 3.9 a new “CommentPress Flat Theme” is included for those who want an alternative layout. If you are upgrading from a previous version of CommentPress (3.0.x – 3.3.x), please follow the instructions in the Installation section before doing so.
For further information and instructions please see the <a href="http://www.futureofthebook.org/commentpress/" rel="nofollow ugc">CommentPress website</a> or visit the plugin’s <a href="https://github.com/IFBook/commentpress-core" rel="nofollow ugc">GitHub repository</a>. Contact the developers by email at <a href="mailto:cpdev@futureofthebook.org" rel="nofollow ugc">cpdev@futureofthebook.org</a>.
For sites hosted in the European Union, please note: the “CommentPress Default Theme” makes use of cookies, but for presentational purposes only. If you intend to use the “CommentPress Default Theme” on a public site, you may need to inform visitors of this.
Many thanks to the following for translations:
<ul>
<li>French – <a href="https://wordpress.org/support/profile/pouhiou">Pouhiou</a></li>
<li>Spanish – Andrew Kurtis from <a href="http://www.webhostinghub.com/" rel="nofollow ugc">WebHostingHub</a></li>
<li>Dutch – Gerrit Jan Dijkgraaf</li>
<li>German – Chris Witte</li>
</ul>

CommentPress Core

CommentPress Core allows fine-grained commenting in the margins of a text. Use it to annotate, workshop or debate a social text in a social context.

WPMailing vs CommentPress Core