Which MIME types are related to file extension ".mso"?

The .mso file extension is associated with 2 MIME types:

A MIME type is a string that tells browsers and other tools how to handle a particular kind of file.

About .mso Files

MSO files are used for different purposes depending on their MIME type.

When associated with the MIME type audio/x-mod, MSO files are MedlySound modules. They are audio files that combine music samples with sequence data.

They hold sample sounds and playback instructions.
They are similar to other tracker formats like MOD.
They can be played using specialized module players (e.g., XMPlay or VLC with the appropriate plugins).

When linked to the MIME type application/x-mso, MSO files are connected with the ActiveMime technology. They typically serve as containers for interactive or embedded multimedia content.

They may contain objects or code meant for dynamic content delivery.
They require specific applications or runtime environments to open and interact with them.
This format is often used in proprietary systems where custom data is handled.

Based on information from FilExt.com, the .mso extension covers at least these two main use cases. Identify the file’s context or MIME type to determine how it should be opened or used.

Relationship between file extension and MIME type

A file extension is a suffix at the end of a filename that indicates what type of file it is. File extensions help both users and operating systems identify what application should be used to open the file.

File extensions are typically separated from the filename by a period (dot) and consist of 2-4 characters, though they can be longer. For example, in the filename "document.pdf", ".pdf" is the file extension.

File extensions are closely related to MIME types, as they both serve to identify the format of a file. However, while MIME types are used primarily by web browsers and servers, file extensions are used by operating systems and applications.

Associated MIME types

audio/x-mod, application/x-mso

FAQs

What is an .mso file?

An .mso file is most commonly an ActiveMime container generated by Microsoft Outlook to store embedded objects in emails. Less frequently, it may be a MedlySound module containing tracker-style audio samples and sequence data.

Why did I receive an 'Oledata.mso' attachment?

This file appears when a sender uses Microsoft Outlook to send an email with embedded objects (like Excel charts or images) that your specific email client cannot render directly. The data is packaged into the application/x-mso format to preserve the object's integrity.

How do I open an MSO file?

If it is an email attachment, you generally cannot open it directly; try viewing the original email in Microsoft Outlook to see the embedded content. If it is a music file, you can play it using media players that support tracker formats, such as VLC Media Player or XMPlay.

Are MSO files safe to open?

Caution is advised. Since ActiveMime files (application/x-mso) can contain macros or scripts, they are potential vectors for malware. Always scan unsolicited .mso attachments with antivirus software before interacting with them.

Can I convert MSO audio files to MP3?

Yes, if the file is a MedlySound module (audio/x-mod), you can use tracker software like OpenMPT or audio converters to export it as MP3 or WAV. However, MSO files created by Outlook cannot be converted to audio formats.

What are the correct MIME types for this extension?

The .mso extension is primarily associated with application/x-mso for Microsoft Office data and audio/x-mod for audio modules. You can verify specific type details on mime-type.com.

General FAQ

What is a MIME type?

A MIME (Multipurpose Internet Mail Extensions) type is a standard that indicates the nature and format of a document, file, or assortment of bytes. MIME types are defined and standardized in IETF's RFC 6838.

MIME types are important because they help browsers and servers understand how to process a file. When a browser receives a file from a server, it uses the MIME type to determine how to display or handle the content, whether it's an image to display, a PDF to open in a viewer, or a video to play.

MIME types consist of a type and a subtype, separated by a slash (e.g., text/html, image/jpeg, application/pdf). Some MIME types also include optional parameters.

How do I find the MIME type for a file?

You can check the file extension or use a file identification tool such as file --mime-type on the command line. Many programming languages also provide libraries to detect MIME types.

Why can one extension have multiple MIME types?

Different programs and historical usage may assign various MIME identifiers to the same file format. Listing them together helps maintain compatibility across tools.