Dan Collis-Puro

This plugin allows users of subscriber- or greater access to subscribe to categories of posts on your wordpress blog. It is probably most appropriate for small to medium sites.
Users can:
<ul>
<li>Choose whether they prefer HTML or text-only email,</li>
<li>Control on a category-by-category basis whether or not they get messages immediately or in a daily or weekly digest.</li>
<li>Control which categories they subscribe to.</li>
</ul>
Site administrators can:
<ul>
<li>Modify reply-to, from, and BCC addresses.</li>
<li>Modify user subscriptions on a users profile page.</li>
<li>Set basic parameters for delivery – how many messages to send at once to avoid usage complaints on shared hosting, for instance.</li>
<li>Bulk edit category subscriptions from the users list.</li>
<li>Exercise complete control over text and HTML templates.</li>
</ul>
Other notes:
<ul>
<li>Scheduled posts are only sent out after the wordpress backend actually publishes them. Put more simply, they work as expected. Be sure wp-cron is running correctly.</li>
<li>Admins can set a “send delay” parameter to allow last-minute edits before sending out a message.</li>
<li>If a message is unpublished after being published, message sending will be aborted. Messages sent already are – well – sent already. We can’t travel back in time (though that’d be a great 2.0 feature). This ensures that old posts needing minor edits don’t get sent out again as updates.</li>
<li>Only messages published after the date of installation are sent out.</li>
<li>Category hierarchy has no effect on subscriptions. If you subscribe to a parent category, you ARE NOT automatically subscribed to its children. This may be integrated into future releases. We may also allow for the subscription to tags or custom taxonomies in future releases.</li>
<li>Bounces ARE NOT handled by this plugin. You can, however, set the “reply-to” and “from” addresses to allow you to collect them in a logical place.</li>
</ul>
Speaking of cron, if you have a low-traffic site (say, for an intranet), you may find that your messages aren’t delivered in the time frame you’re expecting. This is because wordpress scheduled tasks are fired off by visitors to your website – so if you don’t get a lot of traffic, your scheduled tasks won’t run frequently. You can manually create a cron job to hit your wp-cron.php file, something like:
*/15 * * * * wget -q –post-data=”foo” http://www.example.com/yoursite -O – > /dev/null
Remove the “-q” switch above when you test this manually to ensure the request returns a “200 OK” response.
TODO:
<ul>
<li>More template tags.</li>
<li>Better bulk editing features.</li>
<li>Queue management / statistics.</li>
<li>A better template editing interface.</li>
<li>Better debugging – e.g. the ability to send example messages.</li>
<li>More flexible task scheduling.</li>
</ul>
<h3>More Documentation</h3>
See the “Category Subscriptions” options page under your Settings menu. Template tag documentation lives there.
<h3>Other</h3>
This plugin is licensed under the same terms as WordPress itself.
Copyright 2011, The President and Fellows of Harvard College

Category Subscriptions

Allow registered users to subscribe to categories giving them control over delivery times (e.g. daily or weekly digests) and format (html or text).

Timo

<h4>Notify every WordPress post change!</h4>
You want to be notified when one of your contributors have submitted a new post for revision or an editor published one? Vice versa you want to notify your contributors when their posts got published? 
This is just the beginning of what you can achieve with Post Status Notifier (PSN)!
It works with all kind of custom post types, supports all custom taxonomies like categories and tags other plugins are using. You can grab all these taxonomy values and custom fields attached to a post and use them as placeholders in your custom notification texts. PSN has a powerful conditional template syntax featuring many filters and functions to get the most out of the placeholders!
Define as many notification rules as you need with all kind of settings, like custom CC, BCC and FROM emails addresses. PSN is extensible! Build your custom module to implement a new notification service.
PSN works great with plugins like WP Job Manager (<a href="https://www.ifeelweb.de/2014/666/notify-wp-job-manager-listings-wordpress-plugin-post-status-notifier/" rel="nofollow ugc">read more</a>), Calendarize.it (<a href="https://www.ifeelweb.de/2014/748/notify-calendarize-events-wordpress-plugin-post-status-notifier/" rel="nofollow ugc">read more</a>), Crowdfunding by Astoundify (<a href="https://www.ifeelweb.de/2014/706/notify-payments-crowdfunding-astoundify-post-status-notifier/" rel="nofollow ugc">read more</a>) or Advanced Custom Fields, just to name a few. The possibilities are endless. Want to automate your publishing workflow with <a href="https://bufferapp.com/" rel="nofollow ugc">Buffer</a>? No problem!
Plugin homepage: 
https://www.ifeelweb.de/wp-plugins/post-status-notifier/
Always up-to-date online documentation: 
https://docs.ifeelweb.de/post-status-notifier/
FAQ: 
https://docs.ifeelweb.de/post-status-notifier/faq.html
<h4>Features</h4>
Get the <a href="https://codecanyon.net/item/post-status-notifier/4809420?ref=ifeelweb" rel="nofollow ugc">Premium version</a> for all features
<ul>
<li>Define custom notification rules</li>
<li>Support for posts, pages and all custom post types</li>
<li>Support for all post status values</li>
<li>Create custom email texts with support for many placeholders</li>
<li>Manipulate placeholders content with filters to completely adjust the output to your needs (uses the filters of the famous PHP template engine Twig / limited to one filter in the Lite version)</li>
<li>WordPress multisite compatible</li>
<li>Premium version: <a href="https://docs.ifeelweb.de/post-status-notifier/mail_templates.html" rel="nofollow ugc">HTML emails / mail templates</a></li>
<li>Premium version: <a href="https://docs.ifeelweb.de/post-status-notifier/mailqueue.html" rel="nofollow ugc">Mail queue / deferred sending</a></li>
<li>Premium version: Categories filter: Include or exclude categories (even from custom post types) from notifications</li>
<li>Premium version: Supports SMTP. You find all necessary SMTP settings to connect your SMTP server in the options section.</li>
<li>Premium version: Supports user roles (custom roles too) as email recipients</li>
<li>Premium version: Optional logging: Logs status changes based on your rules</li>
<li>Premium version: Dashboard widget showing the latest log entries (can be disabled)</li>
<li>Premium version: Import / Export of your notification rules</li>
<li>Premium version: Copy rules</li>
<li>Premium version: Conditional template syntax (<a href="https://docs.ifeelweb.de/post-status-notifier/conditional_templates.html" rel="nofollow ugc">Manual</a>)</li>
<li>Premium version: Extensible (<a href="https://docs.ifeelweb.de/post-status-notifier/extending_index.html" rel="nofollow ugc">Manual</a>)</li>
<li>Premium version: Custom sender e-mail. Define the notification sender (FROM) per rule or as a default in the options.</li>
<li>Premium version: Mandrill support</li>
<li>Premium version: <a href="https://docs.ifeelweb.de/post-status-notifier/dynamic_recipients.html" rel="nofollow ugc">Dynamic recipients</a></li>
<li>Premium version: <a href="https://docs.ifeelweb.de/post-status-notifier/options.html#late-execution" rel="nofollow ugc">Late execution</a> to support frontend submission plugins as well as possible</li>
<li>Premium version: <a href="https://docs.ifeelweb.de/post-status-notifier/limitations.html" rel="nofollow ugc">Rule trigger limitations</a></li>
<li>Comprehensive documentation</li>
<li>Included translations: english, german</li>
<li>Support in english and german via Zendesk: ifeelwebde.zendesk.com</li>
<li>Tested on Windows, Mac OS and Linux</li>
<li>Built on our ifeelweb.de WordPress Plugin Framework</li>
<li>The Lite version features two notification rules and one CC email</li>
</ul>
<h4>What customers say</h4>
“Great plugin, look through maybe 7 plugins until found this one and it is the best.” 
– misolek
“just got the pro version and it’s working great, awesome plugin man and thanks for your excellent support” 
– nomadone
“This plugin is very intuitive and works great. Very helpful support. Top notch!” 
– Rick
“Thank you for your great support – the plugin works great now and has accomplished what 5 other commercial and free plugins couldn’t – to provide simple and configurable email notifications for WP status changes.” 
– Jon
“just got the pro version and it’s working great, awesome plugin man and thanks for your excellent support” 
– nomadone
<a href="https://codecanyon.net/item/post-status-notifier/discussion/4809420" rel="nofollow ugc">Comment-Source</a>
<h3>Configuration</h3>
Go to the new option page <code>Post Status Notifier Lite</code>. Here you can define custom notification rules.
Here you can find a detailed documentation:
https://docs.ifeelweb.de/post-status-notifier/
<h3>Info</h3>
If you find any bugs please use the comments on the <a href="https://www.ifeelweb.de/contact/" rel="nofollow ugc">plugin’s homepage</a>. Please also contact me for feature requests and ideas how to improve this plugin. Any other reactions are welcome too of course.

Post Status Notifier Lite

Notify on every post change: Flexible rules, custom placeholders and support for all post types and taxonomies.

Category Subscriptions vs Post Status Notifier Lite