[fc417fc802]

That doesn't match my experience at all. If I disable filtering what I see is a slew of ephemeral domains. Without DMARC I'm sure they would instead be official looking and fake.

> It comes from so many sources you can't block them,

Nonsense. If it were really countless fixed sources then a centralized domain blacklist would be sufficient. The issue is that the sources - both domain and IP - are aggressively rotated and even spoofed whenever possible.

[immibis]

That's how it looks now, in a world of ubiquitous spam blockers. Originally, it was each company sending you a few pieces of spam from a legitimate address.