Live Emails - No details when a page is updated and the user is flooded with irrelevant notifications

Steps to reproduce:

1. As admin create a new simple user with your email address
2. Configure the Mail Sending (http://test.xwiki.org/xwiki/bin/view/Administration%20Tests/Configure%20Mail%20Sending)
3. Log in as that user
4. Go to Notifications > Settings
5. Set all Email options to ON
6. Create a filter for an Email option eg. for A new page is created - Filter to only Sandbox pages
7. Select Live
8. Log in as Admin
9. Create a page in Sandbox and one in any other place
10. Update and delete a page
11. Write a comment in a page
12. Wait for some time and check your email

Expected results: The user receives emails with notifications about the selected options.

Actual results: User receives emails with information about the selected options but for the updated pages, in Details, there is no information about the update (Added/removed content) - in my case I've added more text but Details is empty.
Also the user is flooded with some email notifications that are not relevant for him - like the System was updated by superadmin with nothing in Details.
NOTE - I've received many emails with superadmin and admin updates but with nothing in details section and also, I've received notifications about changes I've done with the simple user - which, from my understanding, shouldn't happen, as we don't get notifications about changes we do ourselves.
A total of 12 emails were received.