Stellar Converter for MBOX: Move Thunderbird, Gmail and Apple Mail Into Outlook
Stellar Converter for MBOX is a $39 one-year Windows program that converts mailboxes from Thunderbird, Google Takeout, Apple Mail and about 15 other mail clients into Outlook PST files. It's for people switching to Outlook who want their old mail to come along, and the free version shows the converted mail before you pay.
Outlook has no import option for MBOX, the plain format most other mail programs use. So when you leave Thunderbird, download your Gmail through Google Takeout or inherit an old Apple Mail archive, you have a file Outlook can't read. Stellar Converter for MBOX reads that file and writes a PST that Outlook opens normally.
Quick facts
- Version: 6.3.0.0, released June 2026
- Developer: Stellar Data Recovery (this product used to be called Stellar MBOX to PST Converter)
- Runs on: 64-bit Windows 11, 10, 8.1 and 8. Stellar sells a separate Mac tool
- Reads: Thunderbird, Google Takeout, Spicebird, PocoMail, Eudora, Entourage, Apple Mail, Mulberry, SeaMonkey, Netscape, Claws Mail, Opera Mail, Mozilla Mail, Evolution, Sylpheed, Cone, Mutt and Gnu mail
- Saves to: new PST, EML and MSG (existing PST, Office 365 and PDF need Technician)
- Price: $39 for 12 months
- Free version: previews mail bodies, but won't open attachments or save
- Refund: 30 days from purchase, first purchase only, with conditions
- What we checked: the installer on Stellar's server (14.2 MB, file version 6.3.0.0, dated June 10, 2026), the demo limits in Stellar's manual, the edition table on Stellar's buy page, and the $39 price and 12-month renewal on the order page on November 6, 2026. We didn't convert a mailbox ourselves, so the results below come from the reviewers and users quoted.
Before you buy: check these against your job
- Corporate shows a limit of 3 PST files. The comparison table on Stellar's buy page lists "3 PST Files" for Corporate and "Unlimited PST Files" for Technician. If you have many mailboxes to convert, plan on Technician.
- Outlook must be installed to save a PST. Stellar's FAQ says so plainly, although Thunderbird and the other source clients don't need to be on the PC. Close Outlook before you save.
- The Corporate edition won't add to an existing PST according to Stellar's pricing section, which lists that as a Technician feature, even though the manual describes it as well. Assume you'll create a new PST.
- Try it first. Stellar's refund policy refuses buyers who skipped the evaluation version, and it excludes renewals. Turn auto-renewal off at checkout if this is a one-time move.
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Overview
You pick the mail client from a drop-down list, then point the program at a single file, at a whole identity folder or at a drive to search. It scans and shows a three-pane window like Outlook's, with folders, messages and the open message. Calendars, contacts and tasks have their own views. Then you click Save and choose the format.
The source program doesn't need to be installed. You can copy a Thunderbird profile or a Takeout file to a Windows PC and work from that, which is how most Mac-to-Windows moves will go.
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The first step: choose the mail client the files came from.
Features
Converts 18 kinds of mailbox
Stellar Converter for MBOX reads MBOX files, plus MBX from PocoMail, Eudora and Mulberry, MBS from Opera Mail and RGE from Entourage. Few people need that range, but it's handy if your archive is older than your current mail program.
Moves Google Takeout mail into Outlook
Stellar Converter for MBOX has Google Takeout as a source, so a downloaded Gmail archive turns into a PST. Export your Gmail with Takeout first, and the manual has a section on the steps.
Previews everything before saving
Stellar Converter for MBOX lists converted folders in a tree, with the mail and its fields in the other panes. In the free version you can read mail bodies, which is enough to confirm that the conversion worked, but you can't open attachments.
The three-pane preview of a converted mailbox, with the folder tree on the left.
Contacts and calendars come too
Stellar Converter for MBOX shows contacts, calendar entries and tasks in their own views, where the source mailbox has them. That goes beyond a plain mail copy, although it depends on what the source file stored.
The contacts view after a conversion.
Filters what you save
Stellar Converter for MBOX can save only mail from a date range and exclude chosen senders, so you can leave ten years of newsletters behind. You convert a whole file, then pick what to save. It can't convert a single selected email by itself, according to the manual.
Splits big output automatically
Stellar Converter for MBOX can split a new PST at about 45 GB, so one huge archive doesn't become a single oversized Outlook file.
The save step, where you choose a new PST or another format.
Real-World Uses
- Leaving Thunderbird. The office standardizes on Microsoft 365, and years of local mail have to come along.
- Leaving Gmail. A closing Workspace account is exported through Google Takeout and needs to live in Outlook.
- A Mac user moving to a Windows PC. Apple Mail mailboxes are copied across and converted.
- An old archive. A retired employee's Eudora or Entourage files turn up, and someone needs to search them.
Who It's For, and Who Should Skip It
Buy it if you're moving one or a few mailboxes to Outlook and want a guided tool that shows you the result first. At $39 it's cheap compared with an afternoon of manual import steps.
Skip it if you're not going to Outlook, since the whole product exists to make PST files. Skip Corporate for a company-wide migration or direct upload to Microsoft 365, because that's the Technician edition at $99. If your old mail is still on an IMAP server, adding that account to Outlook will pull the mail across at no cost.
Usage Guide
- Install Stellar Converter for MBOX on a Windows PC with Outlook, and copy your mailbox files there if needed.
- Open the program and choose your Email Client from the drop-down list.
- Click Select File for one mailbox, Select Identity for a whole profile folder, or Find File to search a drive. Apple Mail, Claws Mail, Mozilla Mail, Opera Mail and Sylpheed work with Select Identity only.
- Click Convert and wait for the scan.
- Check the preview, then activate your license.
- Close Outlook, click Save Converted File, choose PST and a location, and apply any filter.
- Open Outlook and use its Import/Export wizard to bring in the PST. The file is named StellarConverted by default.
Where it falls short
- It only does complete files. The manual is clear: "You can only convert a complete MBOX file." Filters apply when saving.
- The free version is a preview. Several reviewers note that you can't test the output in Outlook before paying.
- Large files take longer. Geek Dashboard lists that as a con.
- Windows only, and Outlook is required. A Mac user needs a Windows PC or the separate Mac product.
- No live sync. It works on files, so new mail after the export has to be handled separately.
What Users Say
Reviews are favorable, but there are few detailed independent tests, and several write-ups around the web are sponsored, so we've left those out. Stellar as a company scored 4.8 out of 5 on Trustpilot from 5,601 reviews when we looked, across all its products, and its product page shows 4.9.
Hands-on: Geek Dashboard
Geek Dashboard wrote: "We tested all its features for this review". Its verdict: "Stellar Converter for MBOX is fast and adequately delivers on all the features it advertises." It added, "We love how smoothly it handles large data", while also listing as cons "Takes little more time with Large MBOX file" and "Only the preview option is available in the free version."
Trustpilot
Alberto Lazzarini (October 28, 2026): "I contacted Stellar's chat support before buying Stellar Converter for MBOX". Support and pre-sales help come up again and again in Stellar's reviews.
On the critical side, Trustpilot's complaints across Stellar products center on refunds. unhappy consumer (November 18, 2025, 1 star): "Stellar software's refund policy is a trap." ankit singhal (February 5, 2026, 1 star): "Refund is pending since last 2 months with no reason at all.."
Customers and press, quoted by Stellar
Gladys Rayburn: "I have recently used this software to migrate from Apple Mail to Outlook and found that it converts 100% emails in PST."
Patrick: "I lost all my hopes to move Entourage mails to Outlook 2016. I tried a manual strategy to move MBOX files in Outlook. However, it didn't work."
James Peets: "I was facing a problem in migration and was not aware of the method to migrate from Thunderbird to Microsoft Outlook email application."
Softpedia: "Stellar Converter for MBOX can quickly migrate your MBOX File to Outlook, either in an existing or a completely new PST file."
Windows Instructed, per Stellar, scored it 8 out of 10 on features.
The themes: it's praised for being simple, for covering obscure mail clients and for its preview. The complaints are mostly about the preview-only trial and Stellar's refunds, rather than the conversion itself.
Comparisons
Stellar Converter for MBOX vs doing it by hand
The free route is to add an IMAP account to both Thunderbird and Outlook and drag folders across, or to use a Thunderbird add-on to export. That works for small mailboxes and costs an evening of your time. Stellar is for when the mail is only in files, when the mailbox is large, or when you want to see the result before committing.
Editions and Pricing
| Edition | Price | License | What it adds |
|---|
| Corporate (this listing) | $39 | 12 months | Converts MBOX to PST, MSG and EML from 17+ clients, up to 3 PST files |
| Technician | $99 on Stellar's site | 12 months | Unlimited PST files, existing PST, Outlook profile, Office 365, RTF, PDF and HTML output |
FAQs
Do I need Thunderbird installed to use Stellar Converter for MBOX?
Stellar Converter for MBOX doesn't need Thunderbird or any other source client on the PC. It reads the mailbox files directly, so you only need Outlook for saving a PST.
Can Stellar Converter for MBOX convert a Gmail Google Takeout file?
Stellar Converter for MBOX lists Google Takeout as a source client. It converts the MBOX file from your Takeout download into a PST, which you then import into Outlook.
Can I convert just a few emails with Stellar Converter for MBOX?
Stellar Converter for MBOX converts a whole MBOX file at a time. When saving, you can filter by date range and exclude senders, or use the Technician edition's other save options.
What does the Stellar Converter for MBOX demo let me do?
The Stellar Converter for MBOX demo lets you read mail bodies in the preview, but not open attachments or save anything. That's enough to check that your mailbox converted.
How do I find my MBOX files with Stellar Converter for MBOX?
Stellar Converter for MBOX has a Find File option that searches a drive or folder for MBOX, MBX, MacMBOX and Apple Mail files, which helps if you don't know where a mail client stored them.
Which Outlook versions work with Stellar Converter for MBOX?
Stellar Converter for MBOX supports Microsoft 365, Outlook 2024, 2021, 2019, 2016, 2013 and 2010, according to its current manual. The buy page also lists 2007.
Is there a Mac version of Stellar Converter for MBOX?
Stellar Converter for MBOX is a Windows program, and Stellar's page links to a separate product for Mac. On a Mac you can also copy the files to a Windows PC and convert them there.
System Requirements
- 64-bit Windows 11, 10, 8.1 or 8
- Intel-compatible x64 processor
- 4 GB of RAM (8 GB recommended)
- 250 MB of disk space for installation, plus room for the PST
- Microsoft Outlook, to save a PST
Conclusion
Stellar Converter for MBOX is worth $39 for a one-off move to Outlook from Thunderbird, Gmail, Apple Mail or an old client. The one reason to buy it is how little you have to figure out: pick the client, scan, check the preview, save.
The main reason not to buy is the Corporate edition's limits. If you have more than a few mailboxes, or want to go straight to Microsoft 365, you'll need the $99 Technician edition instead. Check the free preview, and turn auto-renewal off when you check out.
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