FileInfo.com


.MSO File Extension


File Type 1 Inline E-mail Attachment  (Most common)
File Format File
Common? No
File Description File sent with Microsoft Word 2000 e-mail attachments; often named "Oledata.mso;" contains information that allows the attachment to be rendered within the e-mail message.

The Oledata.mso file will appear as a separate attachment on computers that do not have Microsoft Outlook 2000 or later installed.
Program(s) that open mso files Mac: Microsoft Entourage
Windows: Microsoft Outlook 2000 or later

File Type 2 Microsoft Office Macro Reference File
File Format File
Common? No
File Description File created when saving a Microsoft Office document as a Web page; contains information about macros and OLE (Object Linking and Embedding) objects included in the original file; may be referenced by the created Web page as a style sheet.

May be viewed with a text editor, but will be unreadable since the contents are encoded.
Program(s) that open mso files Mac / Windows: Should not be opened manually

Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/mso