There are many complaints, that Redmine is sending too many notifications and is missing functionality to configure them properly… So why then writing this plugin? I believe the problem is in what it sends. You can choose either to receive everything including issue changes, notes, Wiki changes, new messages in boards and so on or just issues. That’s either too much or too little.
Saying I’m just a user of a project. How do I know, when a new version is released?.. Yes, I can subscribe to RSS., but which RSS? News?.. Okay, I can do this. Since Redmine 2.5.x I can even watch news! Assuming, that there will be a news posted about the new release. But, what if not?.. Can I subscribe to files?.. No! Also, there can be no files in the project – users can get code from, e.g., Git. Maybe I can subscribe to versions?.. No! I can subscribe to activities RSS, but it has the same issue as email notifications – too much data! So I can’t know, when new version comes?!.