Email, like the telephone, is polluted into uselessness.
I wonder if Gmail is part of the problem. All the spam I receive at a Fastmail-hosted account is coming from hacked Gmail accounts. Google is doing nothing to stop it, even though a very simple filter at my end can automatically flag it. Gmail's outgoing mail servers are getting reported into blocklist reputation oblivion in recent weeks - could be worth switching to a paid provider.
The spam I'm talking about almost always has "new autobot" or "new cryptobot" in the subject, and usually has an infected PDF attached. A simple outbound check for that would be enough to flag likely compromised accounts. That's the simple filter rule I'm using to kick it automatically into my spam folder for later review.
One of the more egregious servers is mail-lf1-f48.google.com:
https://www.abuseipdb.com/check/209.85.167.48
But it's also coming from mail-yw1-f180.google.com, mail-yw1-f181.google.com and mail-yw1-f182.google.com, and those are just the servers I've seen in the last 24 hours.
https://www.abuseipdb.com/check/209.85.128.180
https://www.abuseipdb.com/check/209.85.128.181
https://www.abuseipdb.com/check/209.85.128.182
I am assuming it is the Google accounts that are compromised, and not Google's own mail servers. But I suppose it's possible that Google itself is pwned.