This was brought up some time ago IIRC, and I think there's an option not to notify the user.
On previous occasions, I did notice that my post count decreased by 1 or 2 but received no notifications when they happened.
I've never heard of that before. I'd be interested if a mod could confirm or deny this.
If an entire thread is deleted or trashed, then you do not receive a notification about your replies in that thread also being deleted. If your post specifically is deleted, then as far as I am aware you will always receive a notification.
As someone has said keeping your own records could be useful. Is there some plugin that can auto archive every post you make?
Loyce's site archives every post (unedited) that is made here:
http://loyce.club/archive/posts/