Using Classic Outlook on Windows for personal email, calendar, and contact management
Adding in my voice as well. I usually always upgrade to the newest versions, but I can't stand New Outlook because it lacks this feature. I want to keep Dark Mode on because it's gentler on my eyes while reading, but keeping the message background color is important for typing/drafting. Now the entire application is far too dark (I notice they also switched the standard dark gray color to almost completely black).