Block Domains/Subdomains

Would like greater flexibility to block incoming email by domains and subdomains.

Currently seeing these spam sources:

collagen.ru.com
erecprimeenhence.ru.com
generatorsolar.ru.com
herpesyl.ru.com
mail.generatorsolar.ru.com
prostavivess.ru.com
truthfinder.ru.com
woodranger.ru.com

breathebp.sa.com
culptaqua.sa.com
servicewarranty.sa.com
superscissor.sa.com

It's obvious what's going on. Effectively, we can't block these.

I would even like to be able to block TLD's.

Maybe a syntax like...

@.ru.com

or

@*.ru.com

or

@**.ru.com

I know that there are possible objections to this but no one using my custom domain is ever going to receive a legitimate message from an ru.com address. Not ever.

I'm a new user but I tried to do research on mailbox.org. If I missed something, apologies.