MSO files exist as 2 different types. Please find information about each of them below.
Type 1: Microsoft Office Macro Reference File
An MSO file is created when saving a Microsoft Office document as a webpage. It contains macros and OLE objects from the original file. The webpage references the MSO file as a style sheet. MSO files ...
An MSO file is created when saving a Microsoft Office document as a webpage. It contains macros and OLE objects from the original file. The webpage references the MSO file as a style sheet. MSO files are encoded and unreadable in a text editor.
These email programs block oledata.mso as a dangerous file. Users can’t view or open messages with this file.
Oledata.mso is the default name Outlook uses for MSO files.
MSO files shouldn’t be opened.
The mso extension relates to Microsoft Organization Chart, for creating organization charts since PowerPoint 95. Now it’s an add-in for Office. The mso file contains a chart imported as an object. Although integrated into Office, the add-in isn’t installed by default.
MSO uses the Microsoft Compound Document Format. The internal structure follows MCDF documentation.
MSO files also store macros and embedded objects when Office documents save as web pages. These encode information not useful to users. Embedded MSO E-Mail attachments need Outlook 2000+ to open. MSO files from MathScript and MedleySound only open in those applications.
The oledata.mso file is an email attachment created by Microsoft Outlook. Outlook adds oledata.mso to emails that contain attached Office documents. Receiving users view the attached Office document...
The oledata.mso file is an email attachment created by Microsoft Outlook. Outlook adds oledata.mso to emails that contain attached Office documents. Receiving users view the attached Office document as part of the email itself. The oledata.mso provides information for Outlook to render the attachment correctly. In other email programs, oledata.mso appears as a separate file, and the Office document does not display inline. In the web version of Outlook, users see the attached oledata.mso files.
You can always open MSO files with Microsoft Outlook 2000 or higher. The latest versions such as Outlook 2010 and 2011 are best. You can also open MSO files in any text editor but may not be able to read the contents. To open an MSO file in Windows, right click on the file then choose Open With. Click Browse to find a text editor like WordPad or Notepad.