Is your Mac Mail not syncing with Exchange email on macOS Catalina? Then there might be issues with the Mail app or your macOS. Sometimes problems like these occur if you are using outdated software. Try updating your macOS Catalina to macOS Big Sur (macOS 11). Still if you have issues with the Mac Mail, troubleshoot the app with the following solutions. Scroll down this page to solve mac mail not syncing with Exchange Catalina issue easily.