I self host. Over the years, I've had both situations with outlook. I've tried many things. As it happens, I noticed my mails have gone through just fine in th

I self host. Over the years, I've had both situations with outlook. I've tried many things. As it happens, I noticed my mails have gone through just fine in the last months, at least to companies using Microsoft services without me doing anything specific, after I threw the towel with Outlook. I did switch VPS providers almost a year ago, though to a provider that I expect to be more filtered (ovh).