What is an MBOX file and why do I need to convert it?

MBOX (Mailbox) is an email storage format used by email clients like Thunderbird, Apple Mail and Gmail Takeout. You need to convert MBOX files when migrating to Outlook, accessing emails without the original client, creating backups in universal formats, or performing forensic analysis.

Which email clients use MBOX format?

MBOX format is used by Mozilla Thunderbird, Apple Mail, Eudora, SeaMonkey, Opera Mail, Entourage, Pocomail, Gmail Takeout exports and many Unix-based mail systems.

Can I convert MBOX to Outlook PST?

Yes, Univik MBOX Converter supports direct conversion of MBOX files to Outlook PST format. All emails, attachments and folder structures are preserved during the conversion process.

Does the converter preserve email attachments?

Yes, all email attachments are fully preserved during conversion. Documents, images, PDFs and other attached files remain intact and accessible in the converted output.

Univik MBOX File Converter

Excellent TrustRating 4.8 (287 reviews)

Convert & Export MBOX Emails

Univik MBOX Converter is professional Windows software to convert MBOX email files exported from Thunderbird, Apple Mail, Gmail Takeout and other email clients into PST, PDF, EML, MSG and 15+ formats with complete attachment preservation.

Free Download
100% Safe & Secure

Buy Now - $49

*Free trial exports first 25 emails per MBOX file. Full version for unlimited conversion.

Universal MBOX Support: Works with Thunderbird, Apple Mail, Gmail Takeout, Eudora, Opera Mail and all standard MBOX variants (MBOXO, MBOXRD, MBOXCL, MBOXCL2).
Complete Data Integrity: All email headers, body content, attachments, embedded images and folder hierarchy preserved exactly as original.
15+ Export Formats: Convert to Outlook PST, individual EML/MSG files, PDF documents, HTML archives and cloud email services.
100% Offline & Secure: Desktop software processes emails locally - your sensitive communications never leave your computer.

Univik MBOX Converter Box

VirusTotal Verified Safe

Certified Clean by 70+ Antivirus Engines. No malware, spyware, or adware.

Supported Email Clients

Thunderbird

Apple Mail

Gmail Takeout

Eudora

Opera Mail

SeaMonkey

Entourage

Pocomail

Export Options

15+ Output Formats

Export your MBOX emails into formats compatible with Outlook, email clients, document archives and cloud services.

Available Export Formats

Outlook Formats

PST, MSG, OST

Direct import into Microsoft Outlook with folder structure and attachments preserved.

Email Formats

EML, EMLX, MHT, MHTML

Individual email files compatible with Windows Mail, Thunderbird and web browsers.

Document Formats

PDF, HTML, RTF, TXT

Archival formats for long-term storage, legal discovery, or sharing emails.

Cloud Services

Gmail, Office 365, IMAP

Direct upload to cloud email services for online access and synchronization.

Key Features

Why Choose Univik MBOX Converter

Professional-grade software with powerful features designed for efficient email conversion and data management.

Batch Conversion Engine

Process multiple MBOX files simultaneously. Handles archives containing tens of thousands of emails efficiently, maintaining consistent formatting and folder hierarchy across all outputs.

Complete Email Preview

Preview all email content before conversion: complete message body, all headers (From, To, CC, BCC, Date, Subject), attachment list, inline images and raw MIME source view.

Complete Attachment Preservation

All email attachments fully preserved: documents, images, spreadsheets, archives and any other file type. Attachments can be extracted separately or embedded in converted emails.

Folder Hierarchy Preservation

Maintains original email organization structure. Inbox, Sent, Drafts and custom folders replicated in output format. Subfolders and nested structures preserved exactly.

Advanced Email Filtering

Filter emails by date range, sender, recipient, subject keywords, attachment presence, or email size. Perfect for legal discovery, compliance audits, or creating focused archives.

Email Header Integrity

All metadata preserved with forensic accuracy: routing headers, timestamps, Message-ID, In-Reply-To, References, X-headers and MIME content types. Essential for legal admissibility.

Corrupted File Recovery

Advanced recovery mode extracts readable emails from partially corrupted MBOX files. Handles truncated messages, encoding errors and malformed MIME boundaries.

Full Unicode Support

Complete support for international characters: UTF-8, UTF-16, ISO-8859, Windows codepages. Handles Chinese, Japanese, Korean, Arabic, Hebrew, Cyrillic and European characters perfectly.

How It Works

Simple Conversion Steps

Follow this easy guide to convert your MBOX email files in minutes.

Step 1: Add MBOX Files

Launch MBOX Converter and click "Add Files" or "Add Folder" to load email archives.

Step 2: Preview Emails

Browse and preview email content, headers, attachments and folder structure.

Step 3: Select Format

Choose your desired output format from 15+ available options.

Step 4: Convert

Click Convert to export emails to your destination folder.

Quick Start Guide

Download & Install: Download Univik MBOX Converter and install on Windows.
Add MBOX Files: Click "Add Files" or "Add Folder" to load email client profiles.
Preview Emails: Browse loaded emails in the preview panel.
Apply Filters: Optionally filter emails by date, sender, or subject.
Choose Format: Select output format from dropdown menu.
Set Destination: Click Browse to select save location.
Convert: Click Convert button. Files ready when complete.

Comparison

Univik vs Other Solutions

See how Univik MBOX Converter compares to other tools and online services.

Univik MBOX Converter

15+ Export Formats: PST, EML, MSG, PDF, HTML, EMLX, MHT, RTF, TXT and cloud services.
Batch Processing: Convert unlimited MBOX files and entire mail profiles simultaneously.
Complete Preview: View full email content, headers, attachments before conversion.
All MBOX Variants: Supports MBOXO, MBOXRD, MBOXCL, MBOXCL2 with auto-detection.
Attachment Preservation: All attachments preserved with original filenames and metadata.
Folder Structure: Maintains complete folder hierarchy in converted output.
Unicode Support: Perfect handling of international characters and encodings.
Corrupted File Recovery: Extracts readable emails from damaged MBOX files.
Offline & Private: Desktop software works without internet.

Other Tools & Online Converters

Limited Formats: Most tools only support 2-3 output formats.
Single File Only: Require manual conversion of each MBOX file separately.
No Preview: Blind conversion without ability to verify content first.
Format Issues: Incompatible with certain MBOX variants causing data loss.
Missing Attachments: Many tools strip or corrupt email attachments.
Flat Structure: Lose folder organization during conversion.
Encoding Problems: Issues with special characters causing garbled text.
No Recovery: Cannot process even slightly corrupted files.
Privacy Risk: Online tools upload your emails to third-party servers.

Customer Reviews

What Our Customers Say

Real testimonials from users who converted their MBOX email archives.

James R.

IT Manager, Chicago, USA

"We migrated 500+ users from Thunderbird to Office 365. Univik MBOX Converter was the only tool that maintained folder structures and handled our 10GB+ MBOX files without crashing. Excellent enterprise-grade solution!"

Lisa M.

Legal Assistant, London, UK

"Perfect for our eDiscovery needs. We converted MBOX archives to individual EML files for our document review platform. All email headers preserved - crucial for proving email authenticity!"

Robert T.

Freelance Consultant, Sydney, Australia

"Finally converted my 15 years of Gmail Takeout archives to PDF! Now I have permanent backups I can search and read without any special software. Worth every penny!"

Technical Data Sheet

Technical Specifications

Complete product specifications, system requirements and compatibility information.

100%

VirusTotal Score: Clean

Verified by 70+ antivirus engines. 100% safe to download and use.

Virus free
Spyware free
Adware free

Supported Input Files

MBOX - All variants:
• MBOXO (Original Unix format)
• MBOXRD (Reversible quoting)
• MBOXCL (Content-Length based)
• MBOXCL2 (Hybrid format)
• .mbx, .mbs file extensions
Unlimited file size supported.

Product Name:	Univik MBOX Converter
Current Version:	25.1 (January 2025)
File Size:	24.5 MB
License Delivery:	Instant via Email
Free Trial:	Free Download 100% Safe & Secure

Latest Release

Version 25.1 Features

Enhanced Gmail Takeout support
Improved large file handling
Advanced date filtering
Better Unicode support
Faster batch processing

Trial Limitations:

Free demo allows unlimited preview. Export limited to first 25 emails per MBOX file. Purchase license for unlimited conversion.

Hard Disk:	100 MB free (500 MB recommended for large conversions)
RAM:	4 GB minimum (8 GB recommended for large files)
Processor:	Intel Core i3 or equivalent

Platforms:

Windows: 11, 10, 8.1, 8, 7 (32 & 64-bit)
Server: 2022, 2019, 2016, 2012

Prerequisites:

Standalone: No additional software required
Offline: Works without internet after install
PST Export: Microsoft Outlook not required

Migration Guides

Step-by-Step Migration Paths

Detailed guides for migrating emails from popular email clients to your desired destination.

Thunderbird to Outlook

Source: %APPDATA%\Thunderbird\Profiles\[profile]\Mail\

Locate MBOX files (files without extension)
Add to Univik MBOX Converter
Select PST as output format
Import PST into Outlook

View Full Guide

Apple Mail to Windows

Source: ~/Library/Mail/V[x]/Mailboxes/

Copy .mbox folders from Mac to Windows
Add .mbox directories to converter
Select EML or PST output
Access emails on Windows

View Full Guide

Gmail Takeout to Local

Source: Google Takeout ZIP file

Download Gmail via Google Takeout
Extract the MBOX file from ZIP
Convert to PDF, EML, or PST
Access Gmail archive offline

View Full Guide

Use Cases

Who Benefits from MBOX Converter

Real-world scenarios where Univik MBOX Converter provides the ideal solution.

Enterprise Email Migration

IT departments migrating thousands of users from Thunderbird to Microsoft 365. Batch processing handles enterprise-scale conversions efficiently.

Digital Forensics & eDiscovery

Forensic investigators and legal teams processing email evidence with complete header preservation for authenticity.

Regulatory Compliance

Organizations meeting email retention requirements (GDPR, HIPAA, SOX) with searchable PDF archives for compliance audits.

Personal Email Backup

Individuals creating permanent backups of Gmail, Thunderbird, or Apple Mail archives in future-proof formats.

Cloud Email Integration

Upload legacy MBOX archives to Gmail, Office 365, or corporate IMAP servers for cross-device synchronization.

Estate & Account Recovery

Families accessing email archives of deceased relatives without needing original email client credentials.

File Locations

Where to Find MBOX Files

Quick reference guide to locate MBOX files from popular email clients.

Mozilla Thunderbird

Windows:

C:\Users\[Username]\AppData\Roaming\Thunderbird\Profiles\[profile.default]\Mail\

macOS:

~/Library/Thunderbird/Profiles/[profile]/Mail/

Linux:

~/.thunderbird/[profile]/Mail/

Look for files without extensions (Inbox, Sent, Drafts)

Apple Mail

macOS:

~/Library/Mail/V[version]/Mailboxes/

Alternative Path:

~/Library/Mail/V[version]/[email]/INBOX.mbox/

Look for .mbox directories containing mbox files

Gmail Takeout

Download Location:

Visit takeout.google.com
Select "Mail" and choose MBOX format
Download and extract the ZIP file
Find "All Mail.mbox" in the Mail folder

Gmail labels preserved as X-Gmail-Labels header

Eudora

Windows Default:

C:\Program Files\Qualcomm\Eudora\

User Data:

C:\Users\[Username]\AppData\Local\Eudora\

Files have .mbx extension in Eudora

Help & Support

Frequently Asked Questions

Find answers to common questions about Univik MBOX Converter.

MBOX (Mailbox) is an email storage format used by email clients like Mozilla Thunderbird, Apple Mail, Eudora and Gmail Takeout exports. It stores all emails in a single text file. You need to convert MBOX files when: (1) Migrating from Thunderbird to Microsoft Outlook, (2) Accessing Gmail Takeout archives, (3) Creating PDF archives for legal discovery, (4) Recovering emails from old backups, or (5) Moving emails to cloud services like Office 365.

Many popular email clients use MBOX format: Mozilla Thunderbird (files without extension), Apple Mail (.mbox folders), Google Gmail Takeout exports, Eudora (.mbx files), SeaMonkey, Opera Mail, Entourage, Pocomail, The Bat! and most Unix/Linux mail systems. Univik MBOX Converter supports all these sources with automatic format detection.

Yes, absolutely! Converting MBOX to PST is one of our most popular features. The converter creates fully compatible Outlook PST files that preserve all email content, attachments, folder structure and email headers. Microsoft Outlook installation is NOT required on the conversion machine.

Yes, 100% attachment preservation! All email attachments are fully preserved during conversion: documents (PDF, Word, Excel), images (JPG, PNG), archives (ZIP, RAR) and any other file type. Attachments maintain their original filenames, sizes and content.

Yes, unlimited file size support! Univik MBOX Converter is optimized for handling large files. We've tested with MBOX archives exceeding 20GB containing 100,000+ emails. The software uses efficient memory management to handle files of any size without crashes.

Simple 4-step process: (1) Download your Gmail data from takeout.google.com, (2) Extract the downloaded ZIP file, (3) Add the "All mail.mbox" file to converter, (4) Choose your desired output format and convert.

Your data is completely safe and private. Univik MBOX Converter is a desktop application that works 100% offline. Your emails are never uploaded to any server. All processing happens locally on your computer.

All MBOX variants supported with automatic detection: MBOXO, MBOXRD, MBOXCL and MBOXCL2. The software also handles files with .mbox, .mbx, .mbs extensions and Thunderbird's extension-less MBOX files.

Yes, powerful filtering options available! Filter emails by: date range, sender, recipient, subject keywords, emails with attachments only, or email size. This is especially useful for legal discovery and creating targeted archives.

The free trial provides full functionality for evaluation: unlimited file loading, complete email preview, all features available. Export is limited to the first 25 emails per MBOX file. Purchase a full license ($49+) for unlimited conversion.

Still have questions? Contact support or Live Chat