Univik Thunderbird Email Converter
The most complete Thunderbird Email Converter, supports multiple profiles, Local Folders, Official & Microsoft Store versions. Preserves read/unread status, attachments and folder structure with 100% accuracy.
*Free trial converts first 10 items per folder. Upgrade for unlimited conversion.

Virus Total Safe
Download with Confidence: Certified Clean by 70+ Antivirus Engines
Preserves All Email Data
Emails
Attachments
Folders
Headers
Read/Unread
Metadata
Local Folders
Complete Support
Unlike other tools, Univik Thunderbird Email Converter supports ALL Thunderbird installations, profiles and folder types.
Downloaded from Mozilla website
AppData\Roaming\Thunderbird
Installed via Windows Store
AppData\Local\Packages\...
Non-account email storage
All local folders included
✓ Fully SupportedWork, Personal, Archive profiles
Auto-detects all profiles
✓ Fully SupportedEmail status preserved
Identify read vs unread emails
✓ Fully PreservedMost Thunderbird converters only work with official installations and ignore Microsoft Store versions, Local Folders or multiple profiles. With Univik, you get complete coverage, no matter how Thunderbird was installed or configured on your system.
Why You Need This
Thunderbird stores emails in MBOX format, which isn't compatible with Outlook, archiving systems or many business tools. Here's why users need a reliable Thunderbird email converter.
Incompatible Format
Thunderbird's MBOX files don't work with Outlook (PST), Windows Mail or most enterprise email systems. Manual methods are complex and error-prone.
✓ Convert to universal formats instantly
Backup & Archiving
Need to create backups in standard formats? Export Thunderbird emails to PST, EML or PDF for long-term archiving and compliance requirements.
✓ Secure archival formats supported
Switching Email Clients
Moving from Thunderbird to Outlook or another email client? The converter ensures all your emails, folders and attachments transfer perfectly.
✓ Seamless email client migration
Risk of Data Loss
Manual conversion methods often lose attachments, break folder structures or corrupt metadata. One wrong step and years of emails could be damaged.
✓ 100% data integrity guaranteed
Large Mailboxes
Years of emails mean huge mailbox files. Free online tools crash or timeout. You need software that handles gigabytes of Thunderbird data reliably.
✓ Handles large mailboxes smoothly
Legal & Forensic Needs
Legal proceedings or investigations require emails in specific formats with preserved timestamps, headers and read/unread status for evidence integrity.
✓ Forensic-grade conversion
Complete Preservation
Every email property, attribute and status is maintained during conversion. Here's exactly what gets preserved.
Multiple Profiles
Power users often maintain separate Thunderbird profiles for Work, Personal and Archive. Our converter detects and converts them all.
Profiles Detected Automatically
📧 Default Profile
Official Thunderbird
C:\Users\...\Roaming\Thunderbird\Profiles\abc123.default
Accounts: 2 | Folders: 47 | Emails: 12,456
📧 Work Profile
Microsoft Store Version
C:\Users\...\Local\Packages\Mozilla.Thunderbird\...
Accounts: 1 | Folders: 23 | Emails: 5,891
📁 Local Folders
Non-account storage
Folders: 8 | Emails: 3,245
Total: 3 profiles | 78 folders | 21,592 emails ready for conversion
Work vs Personal Separation
Many users maintain separate profiles to keep work and personal emails isolated. Convert both independently or together.
Archive Profiles
Old email archives stored in separate profiles? The converter finds and includes them automatically.
Different Installation Types
Have Official Thunderbird AND Microsoft Store version? Both are detected and can be converted simultaneously.
Selective Conversion
Choose specific profiles to convert or convert all at once. Full control over what gets processed.
Local Folders
Local Folders are where many users store important emails that aren't tied to any email account. Our converter handles them completely.
In Thunderbird, Local Folders is a special storage area that exists independently of your email accounts. Users commonly use Local Folders to:
Important: Many converters skip Local Folders entirely. Univik includes them by default, no emails left behind.
📁 Local Folders
├── 📂 Projects
├── Client A (234 emails) ✓
├── Client B (189 emails) ✓
└── Internal (456 emails) ✓
├── 📂 Archive 2023
└── (1,891 emails) ✓
├── 📂 Important
└── (312 emails) ✓
└── 📂 Legal Documents
└── (163 emails) ✓
All Local Folders subfolders and their complete hierarchy are preserved in the converted output.
Beyond Emails
The Thunderbird Email Converter doesn't stop at emails, it also exports your contacts and calendar data to universal formats.
Export your entire Thunderbird Address Book with all contact details preserved.
Export Formats:
Preserved Fields:
Migrate all your Thunderbird calendar events, reminders and appointments.
Export Formats:
Preserved Data:
Smart Filtering
Don't convert everything, use powerful filters to export only the emails you need. Save time and get precisely what you're looking for.
Export emails between specific dates. Perfect for archiving emails from a particular time period, like "all emails from Q4 2024".
Convert only emails from specific senders. Enter an email address or domain to filter emails from particular contacts or companies.
Export emails sent to specific recipients. Useful for extracting all correspondence with a particular client or team member.
Search and convert emails containing specific keywords in the subject line. Find project-related emails or specific topics instantly.
Skip specific folders during conversion. Exclude Spam, Trash or any folders you don't need in your converted output.
Convert emails with/without attachments or extract attachments separately. Control exactly what's included in your output.
📌 Example: Extract Client Project Emails
Filter Settings:
Result:
✓ Found 234 matching emails
✓ Converted to PST with attachments
✓ Folder structure preserved
✓ Completed in 45 seconds
Complete Compatibility
Thunderbird stores data in various file and folder formats. Our converter handles them all seamlessly.
| File/Folder Type | Description | Supported |
|---|---|---|
| MBOX Files (no extension) |
Primary email storage format. Thunderbird stores all emails in a mailbox folder as a single MBOX file with no extension. Example: Inbox, Sent |
✓ Full Support |
| .sbd Folders | Subfolder structure containers. When you create subfolders in Thunderbird, it creates .sbd directories to store them. Example: Inbox.sbd contains subfolders of Inbox. |
✓ Full Support |
| .msf Files (Mail Summary Files) |
Index files containing email headers and metadata for faster searching. The converter reads these for accurate email properties. | ✓ Full Support |
| .mozmsgs Folders | Created when Thunderbird is configured with Windows Search. Contains copies of email data for system search integration. | ✓ Full Support |
| Maildir Directories (cur, tmp, new) |
Alternative storage format where each email is stored as a separate file. Some Thunderbird configurations use this instead of MBOX. | ✓ Full Support |
| .mbox / .mbx / .mbs | Exported mailbox files with explicit extensions. Created when exporting emails using add-ons or third-party tools. | ✓ Full Support |
| EML Files | Individual email files exported from Thunderbird. Each .eml file contains one email with headers and attachments. | ✓ Full Support |
| Address Book (abook.sqlite) |
Thunderbird's contact database file containing all address book entries and contact groups. | ✓ Full Support |
| Calendar Data (local.sqlite) |
Thunderbird Lightning calendar database containing events, tasks and reminders. | ✓ Full Support |
Official Thunderbird (Mozilla):
C:\Users\[Username]\AppData\Roaming\Thunderbird\Profiles\[profile]\Mail\
Microsoft Store Thunderbird:
C:\Users\[Username]\AppData\Local\Packages\Mozilla.Thunderbird_...\LocalCache\Roaming\Thunderbird\Profiles\
Note: You don't need to locate these files manually, the converter auto-detects all Thunderbird profiles and file locations.
Pricing Plans
Flexible pricing options for individuals, professionals and enterprises. All plans include free updates and technical support.
For Individuals
For Professionals
For Organizations
Not satisfied? Get a full refund within 30 days. No questions asked. Your purchase is 100% risk-free.
Secure Payment Methods
🔒 All transactions are secured with 256-bit SSL encryption
15+ Output Formats
The most versatile Thunderbird converter with support for file formats, email clients and cloud services.
Key Features
Professional-grade features designed for accurate, fast and reliable Thunderbird email conversion.
Auto-Detect All Profiles
The converter automatically locates ALL your Thunderbird profiles, Official, Microsoft Store and portable versions. No need to manually find MBOX files or profile folders.
Preview Emails Before Conversion
Read and verify your Thunderbird emails before converting. Multiple preview modes show email content, headers, attachments and raw message data for complete confidence.
Preserves Folder Structure
Your Thunderbird folder hierarchy, Inbox, Sent, Drafts, Local Folders and all custom folders, is perfectly maintained in the converted output. No reorganizing needed.
Read/Unread Status Preserved
Every email's read or unread status is maintained during conversion. After conversion, you can instantly identify which emails were read and which were unread, exactly as in Thunderbird.
100% Attachment Preservation
Every attachment, documents, images, PDFs, archives, is preserved and correctly linked to its parent email. Extract attachments separately if needed.
Local Folders Conversion
Thunderbird Local Folders are fully supported. All emails stored outside of account folders are detected and converted with their complete folder hierarchy intact.
Advanced Search & Filter
Find specific emails before conversion using keyword search, date range filters or sender/recipient filters. Convert only what you need, exactly how you need it.
Bulk Multi-Profile Conversion
Convert multiple Thunderbird profiles in a single operation. Select specific profiles or convert everything at once, ideal for complete migrations and enterprise deployments.
How It Works
No technical knowledge required. The Thunderbird Email Converter is designed for beginners and professionals alike.
Auto-Detect Profiles
All installations found automatically
Preview & Select
Verify content, check read/unread
Convert & Done
All data preserved 100%
Feature Comparison
See exactly why Univik Thunderbird Converter is the most complete solution available.
| Feature | Univik | Tool A | Tool B | Tool C |
|---|---|---|---|---|
| Multiple Profile Support | ✔ | ✘ | ✘ | ✘ |
| Microsoft Store Version | ✔ | ✘ | ✘ | ✘ |
| Local Folders Conversion | ✔ | ⚠ | ✘ | ⚠ |
| Read/Unread Status | ✔ | ✘ | ✘ | ✘ |
| Auto Profile Detection | ✔ | ✘ | ✘ | ⚠ |
| Bulk Multi-Profile Conversion | ✔ | ✘ | ⚠ | ✘ |
| Preview Before Convert | ✔ | ⚠ | ✘ | ⚠ |
| Attachment Preservation | ✔ | ⚠ | ⚠ | ⚠ |
| Folder Structure Maintained | ✔ | ⚠ | ✘ | ✔ |
| Multiple Output Formats | ✔ 10+ | ⚠ 3 | ⚠ 4 | ⚠ 5 |
✔ = Full support | ⚠ = Partial/Limited | ✘ = Not supported
Conversion Integrity
The converter provides a detailed report after every conversion, showing exactly what was processed.
Use Cases
Real scenarios where our Thunderbird Email Converter delivers the perfect solution.
Personal User
Multiple profiles for Work and Personal emails. Needs to convert everything while keeping them organized separately. Auto profile detection saves hours of manual work.
✓ Multiple Profiles ✓ Auto-Detect
Business Migration
Company moving from Thunderbird to Outlook/Office 365. Local Folders contain years of project data that must be preserved. Microsoft Store version used on some PCs.
✓ Local Folders ✓ MS Store ✓ Bulk
IT Administrator
Managing Thunderbird deployments across the organization. Some users have Official version, others Microsoft Store. Need unified conversion solution for all.
✓ Both Versions ✓ Enterprise Ready
Forensic Investigator
Email evidence for legal proceedings. Read/unread status is critical evidence. Must preserve all metadata including timestamps and headers for court admissibility.
✓ Read/Unread ✓ Headers ✓ Timestamps
Compliance Archiving
Regulatory requirements (GDPR, HIPAA) mandate email retention. Need to archive Thunderbird emails including Local Folders in compliant formats like PST or PDF.
✓ PDF Export ✓ Complete Data
Email Backup
Creating reliable backups of all Thunderbird data before upgrading, reinstalling or switching computers. All profiles and Local Folders must be included.
✓ All Profiles ✓ Local Folders ✓ Safe
Data Sheet
Technical Specifications
Score result: Clean
Tested using VirusTotal technology. 100% safe to download and use.
Supported Thunderbird Versions
Official Mozilla Thunderbird (all versions), Microsoft Store Thunderbird, Portable Thunderbird. Converts MBOX files and profile folders directly.
| Name: | Univik Thunderbird Email Converter |
| Version: | 25.12 |
| Size: | 48 MB |
| Delivery: | Free via Email |
| Free Version: |
Latest Release
Version 25.12 Features
|
Trial Limitations: |
Free trial converts the first 10 items from each Thunderbird folder. Upgrade to the full version for unlimited conversion of all profiles and Local Folders. |
| Hard Disk Space: | 150 MB free space required (plus space for converted output) |
| RAM: | 4 GB minimum (8 GB recommended for large mailboxes) |
| Processor: | Intel® Core™ i3 or equivalent (i5/i7 recommended) |
|
Supported Platforms: |
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Pre-Requisites: |
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Help Desk
Frequently Asked Questions
Simple 3-step process:
All emails, attachments, folder structure, read/unread status and metadata are preserved in the resulting PST file.
Yes, fully supported. The Thunderbird Email Converter works with both:
The tool automatically detects the correct profile location for each installation type and loads all mailboxes seamlessly. Most other converters only support the Official version.
Yes. The converter detects and displays ALL Thunderbird profiles on your system:
This is especially useful for users who maintain separate profiles for work and personal emails.
Yes, 100%. Thunderbird Local Folders are fully supported and included by default:
Local Folders often contain the most important archived emails that users have manually organized over years.
Yes. The Thunderbird Email Converter preserves the read/unread status of every email:
After conversion, you can easily identify which emails were read and which were unread, exactly as they were in Thunderbird.
Yes, 100%. Every attachment is preserved during conversion:
Attachments remain correctly linked to their parent emails. You can also extract all attachments separately if needed.
Both are the same Thunderbird application, but installed differently:
| Aspect | Official Thunderbird | Microsoft Store Version |
|---|---|---|
| Download Source | thunderbird.net | Microsoft Store |
| Profile Location | AppData\Roaming\Thunderbird | AppData\Local\Packages\Mozilla... |
| Updates | Manual or auto via Thunderbird | Auto via Microsoft Store |
| Univik Support | ✓ Full Support | ✓ Full Support |
Our converter supports BOTH versions and can even convert them simultaneously if you have both installed.
Absolutely safe. The converter operates in read-only mode:
This is a data-safe conversion process with zero risk to your original emails.
The converter supports multiple output formats:
Choose the format that matches your destination email client or archiving requirements.
The free trial allows you to:
Upgrade to the full version for unlimited conversion of all emails across all profiles and Local Folders.
Still have questions? Contact our support team
Download the free trial and convert your first emails in minutes. Supports all profiles, Local Folders and Microsoft Store version.
Customer Reviews
See what users say about the Univik Thunderbird Email Converter and its unique features.
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