I have a free email account, Yahoo. The account enables Spam filtering, some by Yahoo itself, some by personal selection. Unfortunately, they are so dishonest that they permit all sorts of bogus stuff to get through and sometimes even try to discourage you against designating something as Spam. Once, within the last two months they even permitted an e-address that partly mimicked the US Postal Service!
Anyway, my account allows up to 3 Domain Blocks., the anti-ballistic missile defense against Spam. I just used it against the Paracast domain because even after endlessly marking the emails as Spam, they were getting through fairly often.
There is a catch when employing this feature, however. In general, you entirely forget about it, and it is not part of the menu that you see every day. Once upon a time I blocked a domain, but years later resumed interaction with it. I could never understand why none of their emails were getting through. Eventually I discovered my old setting.
