feature request: filter new user notifications

I’m currently using the free Wordfence plugin and like it a lot and may go to premium. One feature I would love, which probably really belongs in WordPress itself, but if you put it in Wordfence I might pay for it, is to change the Email notifications about new users. I get a stream of idiots signing in to be subscribers to my site who never complete the Email confirmation. I’m sure 99% of them are spammers or worse. I would love it if they were silently dropped from the user list after two weeks non-confirming (you could allow us as administrators to set that and perhaps set whether or not they were sent a warning (I wouldn’t bother). I am sure I an modify the sign in to warn people that they would be deleted after two weeks if they didn’t confirm. I toyed with the idea that you could collect a list of non-confirming Emails and block them but that would be a way to block someone else so that isn’t a good idea (!), however, picking up the IP addresses of these non-confirming attempted sign ups might work. Just a thought but I really would love someone to do it!