MailtoPst
FR
MBOX MSG

Convert MBOX to MSG
Online Tool

Convert MBOX files to MSG format online. Free tool, EU servers, GDPR compliant, auto-delete 24h. No software to install.

Convert now → See how it works
🛡️ GDPR Compliant 🔒 TLS 1.3 Encryption 🇪🇺 Hosted in EU 🇫🇷 Built in France 🗑️ Auto-delete 24h

What is a MBOX file?

MBOX (Mailbox) is the file format used by Thunderbird, Gmail, Unix mail. It stores email messages along with their metadata, attachments, and folder structure.

MBOX files are commonly encountered when:
- Migrating between email platforms — switching from Thunderbird, Gmail, Unix mail to another system
- Email archiving — long-term storage of email communications
- Legal and compliance — eDiscovery and regulatory requirements
- Backup and recovery — protecting email data from loss

While MBOX is widely used in its native ecosystem, working with these files outside of Thunderbird, Gmail, Unix mail can be challenging without proper conversion tools.

What is a MSG file?

MSG (Outlook Message) is the format used by Microsoft Outlook. It provides a structured way to store and organize email messages with full support for attachments, metadata, and folder hierarchies.

MSG is the preferred format for:
- Microsoft Outlook — native file format for import and export
- Cross-platform compatibility — supported on Windows (Outlook preferred)
- Email archiving — reliable long-term storage
- Data migration — widely accepted by email migration tools

By converting to MSG, your emails become accessible in Microsoft Outlook and compatible email applications.

Why convert MBOX to MSG?

Converting MBOX to MSG is essential in several scenarios:

1. Migrating to Microsoft Outlook
If you're moving to Microsoft Outlook, converting MBOX to MSG allows you to import your entire email archive with folder structure and metadata preserved.

2. Cross-platform access
MBOX files require Thunderbird, Gmail, Unix mail to open natively. Converting to MSG makes your emails accessible on Windows (Outlook preferred).

3. Email archiving and compliance
Organizations often need to convert email archives between formats for legal discovery, compliance requirements, or long-term storage strategies.

4. Opening emails without Thunderbird, Gmail, Unix mail
If you receive a MBOX file but don't have Thunderbird, Gmail, Unix mail, converting to MSG lets you access the emails in Microsoft Outlook or any compatible client.

MBOX vs MSG — Key Differences

Feature MBOX MSG
Ecosystem Universal (Thunderbird, Gmail, Apple Mail...) Microsoft Outlook
File structure Plain text, emails concatenated OLE2 compound document
Openness Open standard (RFC 4155) Proprietary Microsoft format
Platform Any OS (cross-platform) Windows (Outlook preferred)
Data types Email only Single email with rich metadata
Free readers Many free clients available Limited

3 methods to convert MBOX to MSG

Method 1: Manual conversion via email client

Import the MBOX file into a compatible email client, then export in MSG format. This requires having both source and target applications installed.

Pros

  • ✓ Free if you already have the software
  • ✓ Full control over the process

Cons

  • ✗ Requires specific software installed
  • ✗ Multi-step manual process
  • ✗ Time-consuming for large files
  • ✗ Risk of data loss during manual steps

Method 2: Desktop conversion software

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

Pros

  • ✓ Direct conversion
  • ✓ Works offline

Cons

  • ✗ Paid ($29-$99)
  • ✗ Windows only
  • ✗ Installation required
  • ✗ Limited file size support
Recommended

Method 3: MailtoPst (online, free trial)

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

Pros

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

Cons

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

Step by step

How to convert MBOX to MSG with MailtoPst

01

Upload your MBOX file

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

02

Choose MSG as output

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

03

Download your MSG file

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

Convert your MBOX to MSG now →

100 MB free credit. No credit card required.

FAQ

Frequently Asked Questions

Can I convert MBOX to MSG without Thunderbird, Gmail, Unix mail?

Yes. MailtoPst reads MBOX files server-side — you don't need Thunderbird, Gmail, Unix mail installed. Just upload the file from any browser on any operating system.

Will my folder structure be preserved?

Yes. MailtoPst preserves the original folder hierarchy from your MBOX file when converting to MSG.

Is MBOX to MSG conversion free?

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

What about attachments and metadata?

MailtoPst preserves all attachments, email headers, timestamps, read/unread status, and other metadata during the conversion.

How large can my MBOX file be?

MailtoPst supports files up to 50 GB with resumable upload technology. If your connection drops, you can resume where you left off.

Related conversions

MBOX → EML MBOX → PST MSG → PST PST → MBOX PST → MSG
See all 30 conversion paths →

Ready to convert your emails?

First conversion free. No credit card required.

Start converting → See pricing