@pluralistic Sir, I do not wish to frighten or alarm you, but dealing with Microsoft with regard to email issues is akin to performing an auto appendectomy with nothing but LSD and Absinthe as an anesthetic.
I wish you luck. Moreso, I truly hope you retain your sanity and composure in the face of the Lovecraftian horrors that lie before you.
Boosted for exposure. gl;hf