[silisili]

I believe that, completely. But keyword silently blocking is an objectively bad approach. Tell the sender it failed if you're so keen to do so. Or tag it with a big POTENTIAL SPAM at the beginning of the message and send it. Or literally any of the dozens of smarter ways of content filtering than (if .xyz in y).

[Zuider]

> Tell the sender it failed...

But if the sender is a bad actor, they can just keep testing until they succeed, which will make fraud worse.

[account42]

Apparently sometimes the sender is not a bad actor.

[Zuider]

Bad actors are why we can't have nice things. Think of how simple, clean and efficient computing would be if we didn't have to keep criminals and idiots at bay.