Microsoft will discontinue support for Windows Mail and Calendar applications on December 31, 2024. Users will lose access to these applications and will be unable to send or receive emails through them after this date. Microsoft encourages users to transition to Outlook for Windows, which is being promoted as the successor to Mail and Calendar. Outlook for Windows is free and features built-in AI capabilities, allowing users to manage multiple email accounts and calendar events in one place. Users can export local emails, calendar events, and contacts to facilitate the transition.