I haven’t productionized this setup (I send maybe a dozen emails a year) but it worked for me ad hoc a couple years back, when I had to send a mail to an Outlook-hosted address and they blackholed everything I tried to send while 250 OKing me.
It's always people self-hosting mail on a shared server in Moldova (because they think it makes them cool) that are complaining.
Which with cheap models like Jev as spam classifiers, this can now become a reality.
The problem is, Google and Microsoft have monopolized the entire email market, so their esoteric deliverability mysticism from 2007 still persists (basically blanket bans on entire IP spaces, locking out anybody trying to send emails on their own).
Email naturally followed this evolution.
https://www.mimar.rs/blog/a-journey-of-my-mx-server-to-new-r...
And yes, it's cool not to have to let scum read your private communications :D