Email is slowly becoming centralised unfortunately as small providers are pushed out by big companies. So it won't be long until we have global email outages.
We practice giving up on the whole ordeal as we have to send another damn email to Microsoft asking for them to investigate their standards-non-compliant black box email filtering systems which even they don't understand.
I tried to go the self-hosted route. It became impossible to manage. I don't know how many hours I sunk in to figuring out why, seemingly randomly, my emails were being marked as spam by Google. If you can't get through to Google, you're effectively invisible for most people
