If it starts in the Folder module (or you want to start in the folder module) and the Mail module is the first one in Folder navigation, you can change a registry key. If you choose a Mail folder as your startup folder, Outlook should start in the Mail module. To open a Search Folder in a non-default data file, use this format, wrapping the path in quotes because it contains spaces: Outlook.exe /select outlook:\\Internet Calendars\Diane_Poremsky_Calendar Outlook.exe /select outlook:\\Archive Folders\Calendar\Testing 3 build 141024) with Office 365 (a software as a service licensing program that makes Office programs available as soon as they are developed). To open a folder stored in another PST in the profile, use the PST name and folder path: Outlook.exe /select outlook:Calendar\Testing Just be aware that when you make the change, it will also alter the default folder for opening or saving your other Office files, including PowerPoint, Word and. If you want to use a different folder in the default message store, you need just the folder names in the path: The basic format is Outlook.exe /select outlook: followed by the folder path and name. At Start menu, Run command (press Windows key + R to open), use the /select command as shown in the samples below, changing the folder path as needed.