An MSG file is an email message, contact, appointment, or task created or saved within Microsoft Outlook. It may contain one or more email fields, which includes the date, sender, recipient, subject, and message body, or contact information, appointment details, and one or more task descriptions. MSG files are also compatible with other programs that use Microsoft's Messaging Applications Programming Interface (MAPI).

MSG file open in Microsoft Outlook 2019 You can create an MSG file by simply dragging and dropping a message, appointment, contact, or task item from an Outlook folder to a folder in Windows Explorer. The message subject will be used as the name of the MSG file. You can open an MSG file in Outlook simply by double-clicking the file. It Outlook is not set as the default application for opening MSG files, you can right-click the file and choose Outlook to open the MSG file. When opened in Outlook, the message will be formatted appropriately to appear the same way it did before it was exported.