Netflix notifications?

So if someone logs on to my Netflix account without knowing it, will I get an email or a notification that someone else has registered?

You get an email

Then there's such a mail that they have detected a suspicious activity and you should change your password

No. I also made it so that I passed on my netflix user from the family account to friends who were able to watch it. Nobody noticed.

You get a general email that someone has logged in, that a suspicious activity has taken place

Normally yes