by Janne Cederberg on WordPress.org
If using Disqus, the authors of posts/pages do not get notified of comments if they're not Disqus moderators. This plugin fixes that.

Notification opt-out in user profile settings is by default not selected. The per-user notification opt-out is useful especially for those users who are Disqus admins to avoid double-notifications.
This plugin notifies post/page author by email of comments posted through the
Disqus Comment System plugin even if the author is not an admin of the Disqus account used for the site.
In other words, this plugin implements the same notification functionality that WordPress ships with out of the box but which is disabled by using the Disqus Comment System.
Confirmed to work with (and to also be needed with) at least Disqus Comment System versions 2.74-2.84.
These sites/blogs describe the same issue that this plugin solves. Using this plugin is simpler though and prevents you from shooting your own leg (by not doing custom hacks)
Contributers to the initial version of this plugin that was released in March 2014 on GitHub