What is MIME type "application/vnd.ms-outlook-pst"?

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

application/vnd.ms-outlook-pst is the MIME type that signals a file used by Microsoft Outlook to store personal folder data.
It handles email messages, contacts, calendar events, tasks, and notes in a single file.
Outlook uses this format for two main types of data storage: one for local archives in PST files and another for offline copies in OST files.

Primary use: Storing and archiving emails and other Outlook items securely on your PC.
Backup: Providing a means to back up or transfer Outlook data.
Offline work: Enabling email access when disconnected from the server by keeping a synchronized local copy.
Synchronization: Supporting efficient syncing between the local storage and the mail server.

Key functionality rests in managing email data effectively with built-in recovery and transfer capabilities.
For more details, refer to Microsoft Support or related technical resources.

Associated file extensions

.pst, .ost

Usage Examples

HTTP Header

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


    Content-Type: application/vnd.ms-outlook-pst

HTML

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


    <a href="file.dat" type="application/vnd.ms-outlook-pst">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.ms-outlook-pst');    
      res.end('Content here');    
    }).listen(3000);

Associated file extensions

.pst, .ost

FAQs

What kind of data does application/vnd.ms-outlook-pst represent?

This MIME type identifies Microsoft Outlook Personal Folder files, commonly known by their extensions .pst and .ost. These files act as local databases that store emails, calendar events, contacts, and tasks directly on a user's computer rather than on the mail server.

Can web browsers display application/vnd.ms-outlook-pst files?

No, web browsers like Chrome, Firefox, or Edge cannot natively render or open Outlook data files. When a server sends this header, the browser will typically prompt the user to download and save the file to their local disk.

How do I configure Apache to serve PST files with the correct MIME type?

To ensure browsers handle the file correctly, add the type definition to your .htaccess file or main configuration. Use the line AddType application/vnd.ms-outlook-pst .pst .ost to associate the extensions with the correct MIME type.

What is the difference between .pst and .ost files using this MIME type?

While both use the same MIME type, PST (Personal Storage Table) files are generally used for local archives and backups independent of the server. OST (Offline Storage Table) files are synchronized copies of data on an Exchange server, allowing users to access mail while offline.

Why do downloads of application/vnd.ms-outlook-pst files often fail?

Outlook data files can grow very large, often exceeding several gigabytes. Downloads may fail if the web server has strict timeout limits or file size caps; check settings like client_max_body_size in Nginx or LimitRequestBody in Apache to ensure large files are supported.

Is it safe to open a file with the application/vnd.ms-outlook-pst type?

You should exercise caution, as these files contain email data which may include malicious attachments or scripts. Always scan a downloaded PST or OST file with antivirus software before importing it into Microsoft Outlook.

Should I use application/octet-stream for Outlook files instead?

It is better to use the specific application/vnd.ms-outlook-pst type rather than the generic application/octet-stream. The specific type helps the operating system and browser understand that the file requires Microsoft Outlook, ensuring the correct icon is displayed and the right application launches upon opening.

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.