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Convert PST to MBOX
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Convert Outlook PST files to MBOX format for Thunderbird, Gmail, and other email clients. EU servers, GDPR compliant, auto-delete 48h.

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What is a PST file?

PST (Personal Storage Table) is Microsoft Outlook's proprietary format, widely used for email archiving in enterprise environments. A PST file is a structured database containing emails, calendar events, contacts, and tasks organized in a folder hierarchy.

PST files are common when:
- Leaving Outlook — years of archived emails are stored in PST files
- Corporate archives — IT departments maintain PST backups
- Legal discovery — eDiscovery processes use PST as the standard format
- Email migrations — moving away from Microsoft ecosystem

While PST is powerful, it's locked into the Microsoft ecosystem. Opening PST files requires Outlook for Windows, making migration to other platforms challenging without conversion.

What is a MBOX file?

MBOX (Mailbox) is the universal, open-standard format for storing email messages. It's supported by virtually every non-Microsoft email client and is the most portable email format available.

MBOX is the native format for:
- Mozilla Thunderbird — import MBOX directly
- Google Gmail — Google Workspace admin tools accept MBOX
- Apple Mail — can import MBOX files
- Postbox, Evolution, Claws Mail — and dozens of other clients

By converting PST to MBOX, you free your emails from the Microsoft ecosystem and make them accessible in any email client.

Why convert PST to MBOX?

PST to MBOX conversion is essential when moving away from Outlook:

1. Migrating to Thunderbird
Thunderbird is the most popular free email client. Converting PST to MBOX lets you import your entire Outlook archive into Thunderbird with folder structure preserved.

2. Importing into Gmail/Google Workspace
Google Workspace administrators can import MBOX files using the data migration tool. Converting PST to MBOX is the bridge between Outlook and Gmail.

3. Moving to Linux or macOS
Outlook for Windows isn't available on Linux. Converting to MBOX gives you access to your emails in Thunderbird, Evolution, or other cross-platform clients.

4. Opening emails without Outlook
If you receive a PST archive but don't have Outlook installed, converting to MBOX lets you read the emails in any free email client.

PST vs MBOX — Key Differences

Feature PST MBOX
Ecosystem Microsoft Outlook only Universal (Thunderbird, Gmail, Apple Mail...)
File structure Binary database (B-tree) Plain text, emails concatenated
Openness Proprietary Microsoft format Open standard (RFC 4155)
Platform Windows (Outlook required) Any OS (cross-platform)
Data types Email + calendar + contacts + tasks Email only
Folder hierarchy Built into file structure One MBOX per folder
Free readers Very limited Many free clients available
Google import Not directly supported Native Google Workspace support

3 methods to convert PST to MBOX

Method 1: Export via Thunderbird (manual)

Install Thunderbird with the ImportExportTools addon. Use it to import the PST (requires Outlook installed), then export as MBOX.

Pros

  • ✓ Free, open-source tools
  • ✓ Good folder structure preservation

Cons

  • ✗ Requires both Outlook and Thunderbird installed
  • ✗ Multi-step manual process
  • ✗ Slow for large archives
  • ✗ Windows only

Method 2: Desktop conversion software

Several desktop converters can handle the PST to MBOX conversion locally. These paid tools typically cost between $29 and $99 per license.

Pros

  • ✓ Direct conversion
  • ✓ Batch processing

Cons

  • ✗ Paid ($29-$99)
  • ✗ Windows only
  • ✗ Installation required
Recommended

Method 3: MailtoPst (online, free trial)

Upload your PST file to MailtoPst, select MBOX as the output, and download. Works from any browser, no Outlook needed.

Pros

  • ✓ First conversion free
  • ✓ No Outlook needed
  • ✓ Works on Mac, Linux, Windows
  • ✓ Preserves folder structure
  • ✓ GDPR compliant, EU servers

Cons

  • ✗ Requires internet connection
  • ✗ Paid after first conversion
Try MailtoPst free →

Step by step

How to convert PST to MBOX with MailtoPst

01

Upload your PST file

Drag & drop or click to upload your .pst file. Files up to 51 GB supported with resumable upload.

02

Choose MBOX as output

Select MBOX from the format dropdown. MailtoPst auto-detects the best conversion settings.

03

Download your MBOX file

Conversion takes seconds. Download your .mbox file or receive it by email.

Convert your PST to MBOX now →

First conversion free. No credit card required.

FAQ

Frequently Asked Questions

Can I convert PST to MBOX without Outlook?

Yes. MailtoPst reads PST files server-side — you don't need Outlook installed. Just upload the PST from any browser on any operating system.

Can I import the MBOX file into Gmail?

Yes. Google Workspace administrators can use the data migration service to import MBOX files. For personal Gmail, you can import MBOX via Thunderbird connected to your Gmail account.

Will my folder structure be preserved?

Yes. MailtoPst creates separate MBOX files for each folder in your PST, maintaining the original organizational structure.

Is PST to MBOX conversion free?

Your first conversion is free with no credit card required. Credit packs start from €4.99.

What about calendar and contacts in the PST?

MBOX only supports email messages. Calendar and contacts from the PST are not included in the MBOX output. If you need these, consider converting to EML (which preserves more metadata) or export them separately.

Related conversions

EML → PST MBOX → PST OLM → PST OST → PST
See all 30 conversion paths →

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