Pi-Mail for protection

Just thinking.
Wouldn't it be nice to have a Pi-Hole mailserver.
Same principle.
Known spamming & malware domains being filtered out.
Example
Normal: something@esso.com
Abuse: someotherthing@esso.mytinkeredname.com

I think this is way way way out of scope for a DNS based adblocker.

Not DNS or something.
A mail server using kind of hosts file for filtering.

This is what puts this request out of scope, in my opinion.

Use https://sourceforge.net/projects/assp/ for that, works very very well.

@jfb It's just a suggestion for something new. Not at all inside PiHole, of course not.
A suggestion for smart guys to think of building a mail server that uses some kind of 'hosts file' to filter out malware/spam. Like PiHole does with domains using hosts files.

@Tntdruid , thanks!