Microsoft / Outlook.com have silently removed connected accounts from outlook.com on July 1st, 2024.
TL;DR: Connected accounts are gone and cannot be fixed 🙁
I only got aware of it as some people told me that my eMails were marked as “unverified sender” on their side. And indeed, eMails were suddenly sent via the outlook email server. Before I sent the mails through the SMTP server of my hosting provider.
Continue reading How to: Migrate from Outlook.com to GMail / Fix connected accounts