What is MIME type "application/vnd.groove-tool-message"?

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

application/vnd.groove-tool-message is a vendor-specific MIME type. It is used by Microsoft's Groove tool. Files of this type store messages and related metadata. They typically use the extension GTM.

This format is designed to package a structured message for collaboration. The MIME type helps software recognize and process these files correctly. It ensures that message content and internal links are preserved during sharing across a network.

Collaboration – Stores messages exchanged in a team environment.
Data Structure – Encapsulates message content with metadata.
Integration – Allows messages to be part of a larger set of interactive documents in a workspace.
Interoperability – Ensures that Groove-compatible software can read and display the message correctly.

For more technical details, visit the IANA registry entry.

Associated file extensions

.gtm

Usage Examples

HTTP Header

When serving content with this MIME type, set the Content-Type header:


    Content-Type: application/vnd.groove-tool-message

HTML

In HTML, you can specify the MIME type in various elements:


    <a href="file.dat" type="application/vnd.groove-tool-message">Download file</a>

Server-side (Node.js)

Setting the Content-Type header in Node.js:


    const http = require('http');    
    
    http.createServer((req, res) => {    
      res.setHeader('Content-Type', 'application/vnd.groove-tool-message');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.gtm

FAQs

Which software is required to open files with the application/vnd.groove-tool-message MIME type?

You typically need Microsoft Groove or its successor, Microsoft SharePoint Workspace, to open these files. They are proprietary files usually associated with the .gtm extension. If you do not have this software installed, the file will likely appear as unreadable binary data.

Can web browsers like Chrome or Firefox display this content natively?

No, modern web browsers do not support rendering application/vnd.groove-tool-message content directly. When a browser encounters this MIME type, it will usually trigger a download prompt, asking you to save the associated GTM file to your local disk.

How do I configure an Apache server to serve Groove Tool Messages correctly?

To ensure your Apache server sends the correct headers for .gtm files, add the following line to your .htaccess file or main configuration: AddType application/vnd.groove-tool-message .gtm. This ensures clients recognize the file type rather than treating it as a generic binary stream.

What does the "vnd" prefix indicate in this MIME type?

The vnd prefix stands for "vendor," indicating that application/vnd.groove-tool-message is a vendor-specific standard rather than a publicly defined IETF standard. It was originally registered by Groove Networks (acquired by Microsoft) for their specific collaboration tool suite.

How do I add support for this MIME type in Nginx?

You can add the type definition to your mime.types file or within a specific server block. Use the following syntax: types { application/vnd.groove-tool-message gtm; }. Reload Nginx after saving the changes to apply the new configuration.

Why is my computer identifying this file as a generic binary file?

If your operating system or browser identifies the file as application/octet-stream, the server likely failed to send the specific application/vnd.groove-tool-message header. This often happens when the web server lacks the specific mapping for the GTM extension.

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 are multiple MIME types listed for one extension?

Different applications and historical conventions may use alternative MIME identifiers for the same kind of file. Showing them all helps ensure compatibility across systems.