Using Outlook for Android in business environments for email and scheduling
I had the same problem suddenly a few days ago, and I solved it by uninstalling Outlook and OneDrive off of my Pixel 7, and cancelling my Office 365 subscription (also my Xbox Game Pass). M$'s greed and incompetence are just too obscene for me to bear anymore. They could have easily tied my account to my install of Outlook mobile WITHOUT hijacking the email address that I used to sign in, which created all sorts of sent mail problems before I realized what they had done.