MSO File

What are MSO files and how to open them

Are you having problems opening a MSO file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your MSO files.

What is a MSO file?

MSO files have multiple uses, and Microsoft Outlook Inline Word is one of them. Read more about the other uses further down the page.

Microsoft Outlook Inline Word File

When you send an HTML message with a Microsoft Word attachment using the Microsoft Outlook email application, the email will have an attachment named Oledata.mso. This file contains information on how to display the Word file correctly in the email.

How to open MSO files

Important: Different programs may use files with the MSO file extension for different purposes, so unless you are sure which format your MSO file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested six different MSO openers which you will find listed below.

Last updated: March 10, 2023

All known file formats using extension .MSO

While Microsoft Outlook Inline Word File is a popular type of MSO-file, we know of 4 different uses of the .MSO file extension. Different software may use files with the same extension for different types of data.

ActiveMime Object File

We know that one MSO format is ActiveMime Object File. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

MedleySound Module

We know that one MSO format is MedleySound Module. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

MedlySound Audio Module

We know that one MSO format is MedlySound Audio Module. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of MSO files. Remember, different programs may use MSO files for different purposes, so you may need to try out a few of them to be able to open your specific file.

Help us help others

File.org helps thousands of users every day, and we would love to hear from you if you have additional information about MSO file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.