I've run an email server for 10 years now and by and large this is the case. I am the only person that uses my domain/IP/mailserver. I know it doesn't send spam

I've run an email server for 10 years now and by and large this is the case. I am the only person that uses my domain/IP/mailserver. I know it doesn't send spam. I've still been blocked by MS Office 365, marked as spam by google, etc, every few years. It's quite a hassle to get unblocked involving lots of lying about having a Microsoft account or the like to tech support till you get to techs who actually know what a mailserver is. Frankly, I'm shocked you've never been arbitrarily blocked and I find your insinuations offensive. The last time I was getting blocked it was the solarwinds fiasco where their internal mail tunneling/forwarding and filtering setup broke all DKIM and suddenly solarwinds users like NOAA.gov were rejecting me and adding me to naughty lists. There was no fallout for the megacorps and their broken setups. There was only damage to independent mailserver operators doing the right thing.