Mine isn't from those email hosts, but it from google cloud or Azure typically (not AWS for whatever reason). Related, the gmail spam filter is terrible.

>Related, the gmail spam filter is terrible. It seems insane that gmail doesnt provide a way to automatically send a mail (eg based on domain, keywords, etc) to spam. I know theres block sender but for example aliexpress uses a different name for every email so that's useless.

Most of my spam is from gmail addresses. Why Google hasn't figured out how to stop the fake Norton renewal notices is just mind-boggling.

Lately I've also been getting a lot from compromised MS365 accounts.

I think you misunderstand the disease.

What this is called is survivorship bias. The question I would ask is how much mail are you not seeing at all because it's dropped at the edge first thing because it's IP block listed?

Next, how much spam are you seeing from them because they and Google are the largest providers on Earth? Kind of like selecting a random person from the population in the US and going "look, it's a white guy". Yea, that's how statistics works.

Lastly, because the are good at blocking spam at the edge, then that's the last bastion of attack for spammers to put their efforts in if they want any return at all.

Sorry but bastions are defensive.

I self-host and don't have a spam filter. Spam makes up about 1 in 5 messages I receive. It's always the same spam campaigns that would be easily filtered with a few regexes.

Self-hosting allows me to use a different receiving address for each entity I contact, so I also know exactly who put me on spam lists.

It's been a while since I've been an SMTP server admin but when I was I managed a few hundred thousand mailboxes under different domains. Most likely know one knows about your domain and it has little traffic. On average I saw users domains get around 5 spam to 1 ham. Of course you have outliers. I had one domain that received around 1000 spam to 1 ham. That was a domain that looked like it could belong to a university and it got absolutely flooded.

Anecdotes are not a great thing to run mail servers on, broad statistics are.

I'm the sysadmin at my company and we regularly get emails spoofing our own addresses! It's wild that Microsoft can't even protect customers when they have all the info to do so.