Personally I would suggest migrating away from Microsoft 365 by using Libreoffice and Thunerbird or SeaMonkey or your favorite email client rather than giving Microsoft any money. However if for some reason you’re absolutely 100% locked-in with Microsoft Office 365 then the linked instructions will at-least save you a little money hopefully. I would still recommend trying to find a solution to why you’re locked in as soon as possible because I’m not sure how long this will last.
Same, we have to use exactly what they give us and nothing else. And that is windows 11 and only Microsoft apps/services. It is just incredible what MS can get away with. Seriously, I had no idea things were this bad, didn’t use any of their services before.