I don't receive any notification

First of all your configuration should be complete and validated - please check this first in the administration area. Second you need a mail server configured in your confluence instance. At last please check if you have used the correct syntax and type the username correctly .. e.g.: @admin:

It is important not to forget the colon after the username and the @ before the username.

How to enable Logging?

Go to your Confluence administration area > Logging & Profiling and add "com.hascode" and the desired log level to the entries. Having done this take a look at your log files.

I don't like this plugin - isn't there any other?

Perhaps the shiny new build-in sharing function in Confluence 3.5 matches your needs