Using classic Outlook for Windows in business environments
Interesting...It let me add my personal email (Gmail) too. Maybe open your own thread to get some fresh attention from the support staff.
Hmm lol you just gave me an idea for a workaround. I *can* add my gmail (which i've transitioned away from, still gotta monitor it though.) It is unassociated with my MS account, not an alias, etc. I'm thinking i should be able to: A) Set my primary alias to my MS email; B) Sign in with MS email; C) Explicitly add my personal email. I wonder if after doing this, i'd be able to remove the MS email... 🤔 That would be crazy. Can't test it until next week though, swapping primary aliases can only be done twice a week.