I used exchangelib with python to organize by labeling and moving to folders emails based on different conditions. Simple string matches as well as iirc even ya

I used exchangelib with python to organize by labeling and moving to folders emails based on different conditions. Simple string matches as well as iirc even yara rule matches. It was surprisingly easy. Nowadays O365 app setup is a pain. But I don't know if you are comfortable coding or not. A simple way is to setup server side rules to move messages to different folders. That's pretty much how every place with high volume shared mailbox works in my experience (1000+ a day).