@erebion @clacke @leyrer I run a server that's provided email to ~15 people for >20 years. The answer is if you do everything right with DKIM, SPF, & DMARC, & never allow spam or bulk email or relaying ever, & you are very *very* lucky, you will only have to open a ticket with microsoft to unblock your domain about 3 times a year, and *most* of your users' important email will deliver to gmail users.

It's hell & it's gotten worse. MS & Google don't care about deliverability from small fry.