When someone send a comment in article, I'm not receiving email notification. I have to enter in the k2 comments section to see if I have new or not. Can you help please? Thank you.

The report comments email address is for just that, for users to report comments that they feel offinsive etc.
in order to get email notifications of comments you need k2autonotify which is j1.5 only at the moment. versions for 2.5 are in the works
if using j1.5 check k2joom.com

When do you estimate k2autonotify to be ready for 2.5?