I have my own domain and email system, I have a spam filter software system in front of it that references a cloud filtering database to make it as good as I can.
I have had this for 20+ years and it has been caught it quite a few of the pwned reports so it is out there.
Despite all of this I receive (past the filter stuff) about 30 emails a day offering me things I never realised I needed.
One of the funniest I ever got was the offer of advance scripts for East Enders. I hate that program.
The world is full of what I would classify as loonies, the Internet seems to give you instant access to all of them!