To open a .mpp file shared via email, in the received email, click on the “Open in Project Plan 365” button. If you have Project Plan 365 installed on your device, the browser will ask you if you want to open the file directly in the app. Click on “Open Project Plan 365” and the app will open. Lastly, Sign In with your email and password for the file to open.

Note: Check the “Always allow projectplan365.com to open links of this type in the associated app” so the browser request message won’t appear every time you open a .mpp from an email and it will open the file directly.