MSG, Outlook Mail Message (.msg)

The MSG Document file format

The MSG file extension is an Outlook Mail Message file. Outlook is a product that was developed by Microsoft to manage e-mail communications and transfer for its users. Anytime you create or save a message in Outlook, the system creates am MSG file. This file contains the important information from the email message, including the body of the message, the name of the sender, the name of the person who will be receiving the message, the subject line and the date. The only types of programs that can open this type of MSG file are those that are compatible with MAPI (Microsoft’s Messaging Applications Programming Interface).

Technical details of MSG files

The MSG file that is created by Microsoft Office is not a simple text file containing all of the information from the message and you cannot open the files via Notepad, Word, etc. The messages are created in a compound file binary format, which means you must be using a MAPI compatible system if you need to view the file. Due to this very specific file structure, it is not always easy to import your Outlook messages into a different email service. The MSG file is created automatically by the system when you execute certain functions. For example, when you save a message, the system automatically exports the contents of your email and creates the MSG file.

More information about the MSG file format

File extension .msg
File category Document
Example file Download example.msg file (31.00 KiB)
Associated programs Microsoft Outlook (Windows)
Encryptomatic MsgViewer Pro (Windows)
BitDaddys Email Open View Pro (Windows)
EZ Freeware Free Opener (Windows)
Kupon.BG Klammer (Mac and iOS)
45 RPM MailRaider (Mac)
Useful links Learn more about the Outlook MSG file extension.
Developer Microsoft
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