I've set up everything according to best practices (SPF, DKIM, TLS, static IP for almost a year, reverse DNS, blacklist removal, spam checks).
I've also repeatedly contacted Microsoft support to get unblocked. All my requests to whitelist the IP in the last year or so have been ignored.
Microsoft is the sole bad actor I've encountered in more of a decade of self hosting email.
On principle, I've decided not to use a different provider, and users on Microsoft services will not get emails from me or from my websites.
This will only change if enough people complain. As a paying O365 customer, I'd encourage you to open support tickets that you're not receiving emails from some the smaller email servers, e.g. those hosted on DigitalOcean.
I've set up everything according to best practices (SPF, DKIM, TLS, static IP for almost a year, reverse DNS, blacklist removal, spam checks).
I've also repeatedly contacted Microsoft support to get unblocked. All my requests to whitelist the IP in the last year or so have been ignored.
Microsoft is the sole bad actor I've encountered in more of a decade of self hosting email.
On principle, I've decided not to use a different provider, and users on Microsoft services will not get emails from me or from my websites.
This will only change if enough people complain. As a paying O365 customer, I'd encourage you to open support tickets that you're not receiving emails from some the smaller email servers, e.g. those hosted on DigitalOcean.