Using older versions of Outlook for Mac for personal email and calendar
If this is the only solution then Microsoft is more **** ier than I ever realised. I'm sick of the poor quality of your products. Biggest con in history how you managed to get the entire World to adopt a standard of mediocrity with your poor quality.
Instead of making obvious suggestions about closing the multiple windows your product opens, why not just fix the product so it doesn't open multiple windows in the first place.
Go to hell Microsoft.