Finding a good email client is way harder than it should be on Windows. Windows Mail is fast, but buggy and weird. Outlook is overkill and doesn’t support Google Calendar. Mailbird was a resource hog (although there were some things to like there). Mailspring was super nice in some regards but not very flexible and tended toward bugs as well.
I don’t want to speak too soon, but I may have found a solution. I’ll keep you posted.