Corbett

Thunderbird Backup Tool

Corbett Thunderbird Backup Tool opens the Mozilla Thunderbird profile already on a Windows PC and saves every account, Local Folders included, as PST, MBOX, EML, MSG, PDF, HTML, CSV or TXT. No passwords are asked for, because the mail is copied from the profile on disk.

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4.6 out of 5 from 683 reviews

Mail comes straight from the Thunderbird profile on this PC. Nothing is uploaded to Corbett.

Free demo, scanned clean on VirusTotal and a 30-day money-back window.

Lifetime licence from $99 Free trial saves 10 emails per folder

Profile coverage

Thunderbird Backup Tool for Every Local Profile

Corbett Thunderbird Backup Tool Copies the Mozilla Profile Already on Your PC

Thunderbird keeps all mail inside one profile folder under AppData. A failed update, a dying disk or a corrupt .msf index can hide years of folders overnight. This copy opens without Thunderbird, so the mail survives whatever happens to the program.

Comes across

Folder tree
Attachments
Inline images
Signatures
Message dates
Read and unread status
Full headers

Folders backed up

Inbox
Sent
Drafts
Archives
Junk
Trash
Local Folders

Saves as

PST
MBOX
EML
MSG
PDF
HTML
CSV
TXT

Not included

Add-ons and themes
Message filters
Saved passwords
Calendar events

Where Thunderbird keeps the profile

In Thunderbird, open Help, then Troubleshooting Information, then Profile Folder. Another route is pasting %APPDATA%\Thunderbird\Profiles into the File Explorer address bar. IMAP accounts sit under ImapMail and POP or local mail under Mail. The tool finds this path on its own.

Export Thunderbird archive folder

Related backup pages: Mailbird backup software, Outlook.com backup tool, Gmail backup tool and Yahoo backup tool. Any other mail source is on the email backup software page.

Quick answer

What Is Thunderbird Backup Tool?

Thunderbird Backup Tool is a Windows program that opens the Mozilla Thunderbird profile already on your PC and saves every account, Local Folders included. No passwords are asked for, because the mail is copied from the profile on disk.

What it saves

Every account, Local Folders and Archives

Where it saves

A folder, an external drive, a NAS share or a live account

Who uses it

Thunderbird users moving to Outlook, a new PC or a new setup

Core features

Thunderbird Backup Tool Across Five Screens

From profile detection to a finished file, in the order the wizard shows it.

Detect

Load the Thunderbird Profile

Go to Open, Desktop Email Clients, Thunderbird Accounts and the configured profile appears with every account inside it. Nothing has to be typed, because the mail is taken from disk rather than from a server.

Default and custom profile paths are found, IMAP, POP and Local Folders are handled alike, and several Thunderbird profiles on one PC show up as separate entries. Thunderbird can stay closed.

Thunderbird folder tree with message counts and checkboxes

Folder selection

Choose the Thunderbird Folders to Save

Every account and its folders appear in a tree with message counts, including Archives organised by year. Greyed out folders can be skipped and empty ones hidden before the backup.

Accounts, folders and subfolders are all selectable. Leave Junk and Trash behind in Thunderbird with one click each.

Message preview

Preview Thunderbird Mail Before Export

Check any message from the profile before it is saved. Next to the standard view sit four analysis tabs, useful when Thunderbird mail has to serve as evidence or an audit record.

Content keeps body, sender, recipients and subject together, message header follows Received lines to the sending server, properties shows size, priority and every enclosure, and hex and raw message bring back the source.

Thunderbird filters by date, sender and size

Selective backup

Filter Thunderbird Mail Before Export

Search panes for folders and for messages work independently. Save one client thread, one financial year or one mailing list from a cluttered profile without touching the rest.

From and To dates, sender, subject or words inside the body, messages carrying attachments only, a size cap for oversized mail and repeat copies skipped.

Thunderbird output format and destination options

Output options

Save Thunderbird Mail as Files or Upload It

Once the preview looks right, choose a folder, an external drive or a NAS share. Thunderbird mail can also be pushed to a live account, the common choice when a user moves to Outlook or Microsoft 365.

PST for Outlook, plus MBOX, EML and MSG copies, and PDF, HTML, CSV or TXT for printing, records and search. Upload folders to Gmail, Microsoft 365 or another IMAP host through the Thunderbird Migrator.

Flexible use

Three Ways to Back Up Thunderbird With One Tool

One profile, several profiles or a move to a new mail service: Thunderbird Backup Tool handles all three. Test your job in free demo before you buy.

Back up one Thunderbird profile

Load the profile, tick folders and save a PST or PDF copy before an update or a disk failure.

Back up several profiles

Every profile found on the PC is listed. Save them together on a shared family or office computer.

Move Thunderbird mail to a new service

Name Gmail, Microsoft 365 or an IMAP host as the target and the folders land in place.

Before starting

Thunderbird Profile Checks Before Backup

Thunderbird Backup Tool works on files on disk, so a few profile checks on the PC matter more than any password.

Check first

Compact folders before the backup

Use File, then Compact Folders in Thunderbird. Deleted mail that still sits inside the MBOX files is cleared out, so the backup is smaller and holds only real messages.

IMAP accounts

Download messages for offline use

With IMAP, Thunderbird may keep only headers locally. Enable offline sync under Account Settings, Synchronization and Storage, so full messages are in the profile before the backup.

Moved profile

Profiles on other drives

A profile copied to a second disk or a USB stick can still be backed up. Point the tool to the folder holding prefs.js and the account list loads from there.

Folder or speed problems inside Thunderbird are covered in Thunderbird not showing folders and Thunderbird running slow.

Working process

How to Back Up Thunderbird Emails in Four Simple Steps

Follow four steps to get a Thunderbird profile onto your drive. Practice on one folder in free demo.

Load the Thunderbird profile

Install Thunderbird Backup Tool, open Desktop Email Clients and choose Thunderbird Accounts. The profile loads by itself, with no password to type.

Select folders and filters

Accounts, Local Folders and Archives show as a tree with counts. Tick the folders to save, then limit by date, sender, attachment or size.

Select format and location

Choose PST, MBOX, EML, MSG, PDF, HTML, CSV or TXT, then point the tool at a folder, an external drive or a NAS share.

Start Thunderbird backup

Press Export and track every folder on the progress screen. A log and a CSV report list all saved mail.

Want screenshots for every click? Follow the Thunderbird backup guide.

Working process

See Thunderbird Backup Tool Back Up a Profile

Prefer step-by-step pictures? The Thunderbird backup guide walks through a profile backup.

Thunderbird backup tool video walkthrough showing folder selection and backup progress

Advanced options

More Thunderbird Backup Features for Large Profiles

Small options that matter on a profile with years of mail in it.

Profile auto-detect

Default and custom paths found on their own

No password asked

Mail is copied from disk, not a server

Several profiles queued

Save every profile on a shared PC

Local Folders included

POP, IMAP and Local Folders alike

Date range filter

Frame the backup with From and To dates

Sender and text search

Look up by sender, subject or words in the mail

Attachment filter

Only mail carrying attachments

Size limit

Leave oversized messages behind

Duplicates dropped

Skip repeat copies on a second backup

Closed Thunderbird works

The program does not need to be open

Folder, drive or NAS

Save to a folder, external drive or NAS share

Log and CSV report

Proof of what was saved

Choose output

Thunderbird Backup Formats and Where They Open

Eight output formats are on offer. Match the format to what you plan to do with the saved mail.

Format	Best for	Opens in
PST	Outlook users and a move to Microsoft 365	Microsoft Outlook
MBOX	Moving mail to a free email client	Thunderbird and Apple Mail
EML	One file per email, easy to search	Windows Mail and most email clients
MSG	Single messages kept as Outlook items	Microsoft Outlook
PDF	Printing and reading without Outlook	Any PDF viewer
HTML	Reading mail with no email client	Any web browser
CSV	Lists of senders, dates and subjects	Excel and Google Sheets
TXT	Plain text archives of mail	Any text editor

Free demo

Test Thunderbird Backup Tool With Real Mail

Install the demo, let it find the Thunderbird profile and export one folder. Open the output before paying anything.

Download free demo

Try before you buy

Free Demo vs Full Thunderbird Backup Tool

Free demo finds the profile, shows every folder, applies every filter and previews mail. Only saving is capped.

Feature	Free demo	Full version
Profile detection and folder list	Yes	Yes
Preview, filter and analysis views	All available	All available
Emails saved per folder	10	Unlimited
Mailbox size limit	Saving stops at 10 per folder	None
Price	Free	$99 one time
Machines per licence	Not applicable	Up to 5
Money back window	Not applicable	30 days

Download free demo Purchase now

Use cases

Who Needs a Thunderbird Profile Backup?

Anyone whose Thunderbird profile holds mail that exists nowhere else.

Users facing an update or a dying disk

A failed update or a corrupt index can hide folders. A copy outside the profile survives.

People moving to Outlook or a new PC

Save to PST or upload straight to Microsoft 365. One licence installs on up to 5 machines.

Offices with POP and Local Folders

Mail pulled by POP lives only on the PC. Back it up before the PC is replaced.

Why Corbett

Why Choose Corbett Thunderbird Backup Tool?

One licence

Covers Thunderbird and 209+ other mail sources

No subscription

Lifetime price from $99

Read-only access

Nothing is changed in the profile

Direct connection

Mail never leaves the PC

Eight formats

Plus upload to a live account

No size limit

Any mailbox size or message count

Free demo

10 emails saved per folder

30 day money back

Refund window on every licence

Before purchase

Free Export Add-on vs Thunderbird Backup Tool

The free ImportExportTools NG add-on exports single Thunderbird folders to EML, MBOX, HTML or PDF from inside the program. For one quick export that is plenty. Here is where a dedicated backup tool goes further.

Task	ImportExportTools NG	Thunderbird Backup Tool
Cost	Free	$99 one time
Export one folder to EML or MBOX	Handles it well	Does it too, the price covers the rest
Outlook PST output	Not available	PST plus seven other formats
Filter by date, sender or size	Folder level only	Fine-grained filters before export
Header, hex and raw views	Thunderbird own source view	Four analysis tabs in the preview
Thunderbird must be running	Yes, the add-on works inside it	No, the profile is opened directly
Several profiles or accounts	One folder or account at a time	All accounts in one session
Upload to Gmail or Microsoft 365	Not supported	Direct IMAP upload built in

Rows tinted green are where the free add-on holds its own.

For a quick single-folder export, ImportExportTools NG is free and works well. The steps to Export MBOX from Thunderbird are covered in that guide.

Global recognition

Thunderbird Backup Tool Users Trust

Users rate Corbett backup software 4.6 out of 5 across 683 reviews, and software directories list it.

CNET
Download.io
UpdateStar
TopSoftware Advisor
SaaSHub
Uptodown

Specifications

Thunderbird Backup Tool Hardware Needs

Windows Versions Supported by Thunderbird Backup Tool

Download details

Released: Dec 2020
Download size: 87.4 MB
Trial limit: 10 emails per folder
Delivery: Download link and key by email
Licence: Lifetime, up to 5 machines

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System

Hard disk: 150 MB to install, plus room for output
RAM: 4 GB minimum
Processor: 1 GHz, 2.4 GHz advised
Rights: Run as Administrator
Profile: Thunderbird profile on the same PC

Supported editions

Windows 11, 10, 8.1, 8 and 7, in 32 and 64 bit. Windows Server 2025 down to 2008. Outlook is not required.

No macOS or Linux build.

Corbett has built Windows email utilities since 2020. Thunderbird Backup Tool questions are answered by its own engineers.

Full specification

Thunderbird Backup Sources and Output Formats

Complete source and output list for Corbett Thunderbird Backup Tool.

Goes in

Thunderbird profile sources

Mail source: Mozilla Thunderbird profile on disk
Sign-in: None, no password needed
Profile location: Default and custom paths found automatically
Account types: IMAP, POP and Local Folders
Folders: Inbox, Sent, Drafts, Archives, Junk, Trash and own folders
Profiles per session: Several, listed separately
Profile size limit: None, 30 GB and more export
Access mode: Read-only, nothing changed in the profile
Filters: Dates, sender, subject, text, attachment, size
Local files opened: PST, OST, MBOX, EML, EMLX, MSG

Comes out

Backup destinations

Client formats: PST for Outlook, MBOX, EML, MSG
PST options: Unicode PST, split by size, merge profiles into one PST
Save locations: Folder, external drive, NAS share
Document formats: PDF, HTML, CSV, TXT
Upload targets: Gmail, Microsoft 365 or an IMAP host
Separate extraction: Attachments, addresses and phone numbers
Repeat backups: Date filter and duplicate skip, no incremental mode
Closed program: Works with Thunderbird shut
Reports: Live progress, log and CSV report
Restoring mail: Email Recovery Software

To convert saved files later, use email converter tool or single-format PST File Converter Tool, MBOX File Converter and EML Converter Tool. To move a full Thunderbird profile to another mail service, use the Thunderbird Migrator. To open a saved file without exporting, use free email viewer software.

User testimonials

Thunderbird Backup Tool Reviews

From 683 reviews of the Corbett backup wizard that opens Thunderbird profiles.

4.6 out of 5

Pulled from 683 reviews on rating sites and customer emails. Below are three, quoted exactly.

Recommended by a friend

It is an amazing software to download all Thunderbird emails to a number of applications. One of my friends recommended this tool to me for its efficient and fast backup process, and it worked well.

Lawrence Smith

Many formats, no downtime

I loved the Mozilla Thunderbird backup tool because it was able to backup my entire Thunderbird emails in numerous file formats. Also, it can save data files without any downtime.

Katherine William

Bought the licensed edition

The software's advanced functionality let me buy its licensed edition. It is such a fantastic toolkit that works with my expectations. Also, it allows you to store data on over 100 platforms.

Taniya Rao

Best practice

How to Keep Your Thunderbird Backup Safe

Saved mail is only useful if it opens later. These four habits protect your Thunderbird archive.

Back up before updates

Copy the profile before a Thunderbird update, a Windows reinstall or a disk swap.

Open a sample file

After saving, open a handful of messages. Confirm folders, photos and attachments came across.

Keep PST and PDF

Repeat the backup with a second format. PST for Outlook and PDF for reading anywhere is a common pair.

Store a copy elsewhere

Keep one copy on a home drive and one on a USB stick or NAS, named by address and date.

Common questions

Thunderbird Backup Tool FAQs

Profiles, offline mail, formats and the limits of a disk-based backup.

How do I back up Thunderbird emails with Thunderbird Backup Tool?

Install the tool, open Desktop Email Clients and choose Thunderbird Accounts. Your profile loads automatically. Preview the folders, select a format and start the backup.

Do I need my Thunderbird or email password?

No. The tool takes mail from the profile on your disk, not from the mail server, so no account password is involved.

Where is my Thunderbird profile on Windows?

Typically under %APPDATA%\Thunderbird\Profiles in a folder ending in .default-release. In Thunderbird, Help, Troubleshooting Information, Profile Folder opens it directly.

Some IMAP folders come out empty. Why?

Thunderbird only had headers for them. Tick Keep messages for this account on this computer under Synchronization and Storage, let Thunderbird download, then back up again.

What if the profile sits on an old PC?

Copy the profile folder from the old computer, then point the tool at it. Every account inside loads as if Thunderbird were still installed there.

Will my Thunderbird folders keep their order?

Yes. Accounts, Local Folders, Archives by year and every subfolder come out in their original order. A flat single folder is optional.

Does it handle several Thunderbird profiles?

Yes. Every profile found on the PC is listed and they can be saved together, handy on a shared family computer.

Are attachments and contacts kept?

Attachments stay with every message. Extract can also pull attachments, email addresses and phone numbers into separate files, which covers most contact lists.

Is Thunderbird required to be installed?

The tool needs the Thunderbird profile, not the running program. With Thunderbird installed it is found automatically. A copied profile folder can be loaded by hand.

Can a repeat backup add just recent Thunderbird mail?

There is no incremental mode. Set a start date matching the last backup and enable duplicate skipping, so a repeat backup stays quick.

How large a Thunderbird profile can it export?

Profiles of 30 GB and more export in the full version. Because mail comes from disk, speed depends on the drive, not on a mail server.

Can I move Thunderbird mail to Outlook or Gmail?

Yes. Save to PST and open it in Outlook, or upload folders straight to Gmail, Microsoft 365 or any IMAP account with the Thunderbird Migrator.

Does my Thunderbird mail leave my PC?

Only if you choose an online destination. For file backups everything stays on your own drives and Corbett receives nothing.

Does it support macOS or Linux?

No. It is a Windows program. Mac or Linux Thunderbird profiles can be copied to a Windows PC and backed up there.

What does the Thunderbird demo allow?

It finds the profile, shows the full folder list and unlocks preview and filters. Output is capped at the first 10 emails of every folder, enough to judge the result.

Why compact folders before a Thunderbird backup?

Deleted mail can stay inside the MBOX files until folders are compacted. File, then Compact Folders clears it, so the backup is smaller and holds only real messages.

Can I back up a profile saved on a USB stick?

Yes. Point the tool to the folder holding prefs.js and the account list loads from there.

Can I limit the backup to one sender or year?

Yes. Filters cover From and To dates, sender, subject, words in the mail, attachments and size. Only matching mail is written.

Does the tool change my Thunderbird profile?

No. It only reads the files. Your folders, filters and settings stay exactly as they were.

Can I open a saved file without Thunderbird?

Yes. Open it read-only in the free email viewer software, or see Open MBOX file.

Does it work on Windows 7?

Yes. Windows 11 and 10 are supported along with all older versions.

How much does Thunderbird Backup Tool cost?

One payment of $99 buys a lifetime licence for up to 5 machines, with a 30 day refund window.

Step by step

Thunderbird Help Guides and Tools

Guides for common jobs around a Thunderbird profile backup.

Exporting from Thunderbird

Moving Thunderbird

Fixing problems

The full list of providers sits on the email backup software page. Moving a full Thunderbird profile uses the Thunderbird Migrator, and putting saved mail back into an inbox uses email recovery software. Related backups: Outlook.com backup tool, Office 365 backup tool, Gmail backup tool, Yahoo backup tool, iCloud backup tool, Google Workspace backup tool and Webmail backup tool.

Get started

Protect a Thunderbird Profile Today

Download the demo, let it find the Thunderbird profile and export a sample from every folder. The full licence is a single $99 payment and can be refunded within 30 days.

Download free demo Purchase now

87.4 MB · Windows 11 to 7 and Windows Server 2025 to 2008 · 30 day money back