Corbett

MBOX Converter

Corbett MBOX Converter converts MBOX, MBX and MBS mailbox files in batch with folders, attachments and headers kept. It opens any MBOX file, whatever program wrote it, and exports to 10+ file formats or a live mailbox. Windows software with a free demo.

Download free demo Purchase now

4.9 out of 5 from 2,162 reviews

Files are converted on this PC. No MBOX file ever goes to Corbett.

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

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

File facts

MBOX Converter for Any MBOX File

An MBOX file stores a full mail folder as one long text file, every message stacked under a separator line. Few programs open it and fewer cope once it grows past a few gigabytes. MBOX Converter splits that file back into separate messages, keeps folder names and attachments and converts the lot in one batch.

Kept in output

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

MBOX sources

Google Takeout
Thunderbird
Apple Mail
Eudora
Postbox
Opera Mail
Orphan .mbox files

Outputs

PST
EML
PDF
HTML
CSV
TXT
Gmail and Microsoft 365
Any IMAP host

Not converted

Client settings
Saved searches
Filter rules
Calendar entries

What sits inside an MBOX file

MBOX is plain text. Every message begins with a line starting From and a space, then headers, body and Base64 attachments. Variants named mboxo, mboxrd and mboxcl treat that From line differently, which is why quick scripts often break mail apart. MBOX Converter handles those variants.

Open MBOX file

Core features

MBOX Converter in Five Steps

Load the files, check the mail, set the format. These are the screens a conversion passes through.

Load

Add MBOX Files or a Folder

Open, Email Data Files, MBOX loads one file or a directory holding dozens. Thunderbird profiles and Apple Mail packages are recognised, and a Takeout file can go in straight from the download.

File and folder browsing
MBX and MBS extensions accepted
Google Takeout .mbox opened directly
Multi-gigabyte files handled

MBOX folder tree with selection checkboxes

Folder selection

Select the MBOX Folders to Convert

MBOX Converter shows every loaded file in a tree with its message count. Untick spam or old newsletters and only the useful mail is converted.

Checkboxes on files and subfolders
Message totals beside names
Folder names kept from the source
Unwanted files left out

Message preview

Read MBOX Mail Before Converting

MBOX Converter displays any message beside four analysis tabs, handy for checking dates and senders before a legal or audit export.

Content renders the body with sender, date and subject
Message header lists every header field the message carries
Properties reports size, encoding and attachment names
Hex and raw message reproduce the stored text byte for byte

Selective backup

Convert MBOX Emails by Date or Subject

Two search boxes in MBOX Converter narrow files and messages separately. Convert one tax year, one sender's mail or anything with a PDF attached and skip the rest.

Start and end date
From, To or Subject match
Mail with attachments only
Size limit for messages
Duplicate copies skipped
Attachments pulled out alone

Output options

Select an MBOX Converter Output

Save converted MBOX mail on disk, or upload it straight to a mailbox. The Export button lists 10+ formats and every one keeps folder names and attachments.

PST, EML, PDF, HTML, CSV and TXT files
Gmail, Microsoft 365, Yahoo or any IMAP account
Mail still on a server rather than in files belongs in the IMAP Migration Tool
Only need to read the files? Try the Free MBOX Viewer first

Before converting

MBOX Converter File Prep

Most failed conversions trace back to the file, not to MBOX Converter. Three checks save a rerun.

Google Takeout

Unzip the Takeout archive first

Takeout delivers a .zip or .tgz holding a Mail folder. Extract it, then load the .mbox file inside, usually named All mail Including Spam and Trash.

Apple Mail

Point at the mbox file in the package

An Apple Mail export is a .mbox folder holding a file called mbox and a table_of_contents. Copy the full package to the Windows PC and load the inner mbox file.

Thunderbird

Skip the .msf files

Thunderbird keeps an MBOX file without extension next to a .msf index for every folder. Load the file without extension. The .msf holds only summary data.

Exporting the source files is covered in Export Gmail emails to MBOX and Export MBOX from Thunderbird.

Free demo

Convert a Sample With MBOX Converter

Install the demo, load an MBOX file and convert 10 emails from every folder. Open the result in Outlook or a PDF reader before buying.

Download free demo

Before purchase

Free MBOX Viewer vs MBOX Converter

Corbett's Free MBOX Viewer opens and reads MBOX files at no cost. When the mail has to live somewhere else, in Outlook, a PDF bundle or a cloud mailbox, MBOX Converter takes over. Here is where the free one stops.

Task	MBOX Viewer	MBOX Converter
Cost	Free	$99 one time
Read MBOX mail	Reads every message	Reads too, plus export
PST for Outlook	Not offered	Full PST output
Date and sender filters	Search only	Filters applied to export
Upload to a mailbox	No	Gmail, 365 or IMAP
Batch of files	Opens files	Converts folders in one run
Pull addresses	No	Addresses, phones, attachments
PDF for records	Print only	PDF output

Green rows show jobs the free viewer already covers.

To read old mail without moving it, the free tool costs nothing. Download it from the Free MBOX Viewer page.

Specifications

MBOX Converter System Specs

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

Download Now

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
Input: MBOX, MBX or MBS files

Supported editions

Windows 11, 10, 8.1, 8 and 7, 32-bit or 64-bit, and Windows Server 2008 through 2025.

No macOS or Linux build.

Corbett has built Windows email utilities since 2020. MBOX Converter support comes from the team that maintains the code.

Working process

MBOX Converter Video Demo

Want stills instead? The MBOX to PST guide covers the same run one screen at a time.

Common questions

MBOX Converter FAQs

Files, formats, Takeout quirks and what the demo converts.

How do I convert MBOX files?

Open, Email Data Files, MBOX and load your files or a folder. Tick the folders you want, select a format under Export and press Save.

Which programs create MBOX files?

Thunderbird, Apple Mail, Eudora, Postbox, Opera Mail and Google Takeout all write MBOX. The converter reads your file the same way whatever the source.

Will Google Takeout files work?

Yes. Extract your Takeout archive and load the .mbox inside. Mail and attachments convert normally.

Does it convert Apple Mail exports?

Yes. Copy the .mbox package to your Windows PC and load the mbox file inside it.

Can I convert many MBOX files at once?

Yes. Load a folder and every MBOX file in it converts in one batch with its folder name kept.

Are attachments kept?

Yes. Attachments stay inside every message in PST and EML output. You can also save them to a separate folder.

Can MBOX go straight into Gmail?

Yes. Select Gmail, enter a Google app password and your messages upload over IMAP.

Can I upload MBOX to Microsoft 365?

Yes. Select Microsoft 365 and approve the Microsoft login. Folders appear in Outlook on the web.

What is an MBX or MBS file?

Older names for the same mailbox format, used by Eudora and a few other clients. The tool reads them like MBOX.

How large can an MBOX file be?

There is no cap in the full version. Takeout files of 20 GB and more convert, given free disk space for your output.

Do I need Thunderbird or Apple Mail installed?

No. The converter reads MBOX files on its own, so orphan files from a dead PC or an old Mac work too.

Can I extract email addresses from MBOX?

Yes. Extract saves sender and recipient addresses, phone numbers or attachments to separate files.

Does Corbett receive my MBOX files?

No. Conversion runs on your PC. Only an upload to Gmail or another account sends mail out, and then straight to that provider.

Can I convert MBOX on a Mac?

Not on the Mac itself. Copy your MBOX files to a Windows PC and convert them there.

What does the MBOX Converter demo convert?

It converts 10 emails from every folder while preview and every filter stay open, enough to judge the output before buying.

Step by step

MBOX File Guides

Walkthroughs for MBOX files from different sources.

For Outlook users

Cloud accounts

Other formats

Mail that has to move between live accounts goes through the Email Migration Tool . For server to server jobs there is the IMAP Migration Tool. Every other file type Corbett converts sits under the email converter tool. Putting converted files back on a mail server is handled by the email recovery software. Files can be read without converting in the email viewer software. Format pages: MBOX to PST Converter and MBOX to PDF Converter. Also see the MBOX to EML Converter, Thunderbird Backup Tool, Gmail Backup Tool, Thunderbird Migrator and Gmail Migration Tool.

User testimonials

MBOX Converter Reviews

2,162 ratings collected for the Corbett MBOX conversion wizard.

4.9 out of 5

Collected across 2,162 reviews gathered through download portals and support inboxes. The three quotes below keep their original wording.

Thunderbird to Outlook, intact

I like how it is easy to use as I move all my emails from Thunderbird to Outlook. It worked so well that my folder structure and attachments were intact after converting them.

Jenna

Old MBOX files to PDF

I had a batch of old MBOX files that needed to be converted into PDF. With the help of this converter, my process of converting has become so simple. I highly recommend this tool to everyone.

Michael

Date filter did the job

I loved the option of filtering the emails by date. This feature helps me to convert specific emails from MBOX files. Plus with so many export options there's no need for any other tool to convert the files.

Daniel

Get started

Start With MBOX Converter Today

Get the demo, convert a sample of real MBOX mail and inspect the output. A lifetime licence is $99, refundable 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