Files with mso extension can be found as special attachment for Microsoft Word documents send through e-mail to MS Outlook. Contains data to properly render the document as a HTML webpage in Outlook.
There are 3 other file types using
the MSO file extension!
.mso - Microsoft Organization Chart chart data
.mso - MedlySound module
.mso - ActiveMime object
Software that open mso file
MSO file extension - OLE web page storage stream
What is mso file? How to open mso files?
File extension mso seems to have been in the past used for a special attachment format generated by earlier versions of Microsoft Word (and possibly other MS Office programs) in conjunction with earlier versions of Microsoft Outlook.
Typically this happens when Word is used as email editor, the document is being send out as the email body which is in HTML format. Usually found as oledata.mso file.
The mso file contains necessary information to properly render the attachment in the message in its originating program. This happens when the file is opened in Outlook 2000 and 2003, and was fixed in 2007 and later. However the "problem" is generated by the sender, not by the recipient.
If you have Outlook installed, you will not see this file, as the document will be rendered properly in HTML using the data from oledata.mso.
However if your computer does not have Outlook installed and you use other mail client, you will see the oledata.mso file as an attachment.
The mso file does not contain the actual document, which can be either found in the body of the e-mail message, or as another attachment as .doc file.
You can disable this function in Word by:
- Open Microsoft Word
- Go to Tools ► Options… ► General tab
- Click the button E-mail Options…
- You can set the HTML filtering options on the General tab
- Confirm it by OK
This is not exclusive to Word, but just happened mostly with the word-processor. But same files were for example generated by FrontPage or when saving documents to office html format and possibly also with broken links to files like filelist.xml, editdata.mso and oledata.mso.
Updated: April 19, 2024
The default software associated to open mso file:
Company or developer:
Microsoft Corporation
Microsoft Word offers powerful word processing and text editor features that allow users to easily create documents. Almost every, if not every, computer user knows .doc and .docx Word documents.
Company or developer:
Microsoft Corporation
Microsoft Outlook is a professional e-mail management tool and personal information manager distributed with the Microsoft Office suite. Outlook integrates the e-mail application, calendar, task manager, contact manager, and note-taking into one application.
List of software applications associated to the .mso file extension
Recommended software programs are sorted by OS platform (Windows, macOS, Linux, iOS, Android etc.)
and possible program actions that can be done with the file: like open mso file, edit mso file, convert mso file, view mso file, play mso file etc. (if exist software for corresponding action in File-Extensions.org's database).
Hint:
Click on the tab below to simply browse between the application actions, to quickly get a list of recommended software, which is able to perform the specified software action, such as opening, editing or converting mso files.
Programs that can create mso file - OLE web page storage stream
Programs supporting the exension mso on the main platforms Windows, Mac, Linux or mobile. Click on the link to get more information about listed programs for create mso file action.
Microsoft Windows:
Main software associated with mso file by default: Microsoft Word
Other suggested software: Microsoft FrontPage (obsolete/discontinued)