Reviewed by Shubham Dixit, Independent Expert in Email Forensics and Data File Conversion. Shubham is an external reviewer and not a PCDOTS employee.
Table of Contents
Need your MDaemon mails inside Thunderbird? Maybe the server is being retired, or you just want a free desktop client holding a local copy of everything. Either way the move is very doable. Here’s the full route, including the import step most guides forget.
Summary
To move MDaemon mails to Thunderbird, load your MDaemon files into PCDOTS Email Converter, click Export, choose Thunderbird and save the output as MBOX. Then import the MBOX files into Thunderbird with the ImportExportTools NG add on. Folder structure, attachments and original dates stay intact through the whole process.
Why move MDaemon mails to Thunderbird?
Moving from MDaemon to Thunderbird means converting server side mailboxes into a format a free desktop client can read. The two products solve different problems, so this migration usually happens for one of 4 reasons.
- Server retirement. The company is shutting down or replacing its MDaemon server, and staff still need their old mail on their desks.
- Local archives. Departing employees, finished projects or compliance copies need a readable offline archive, and Thunderbird is a free way to keep one.
- Cost. Thunderbird costs nothing per seat. For small teams that only need email, that math is hard to argue with.
- Independence. A desktop client keeps working even when the old server account is deleted. Your mail belongs to you, not to a login.
Whatever your reason, the technical path is the same and it runs through one file format.
Why MBOX is the bridge between MDaemon and Thunderbird
Here’s the part that makes this migration logical instead of magical. MDaemon stores each message as an individual plain text file inside per user folders on the server, normally under the MDaemon\Users directory. Thunderbird stores mail differently. It keeps each folder as one MBOX file, a plain text container holding all the messages of that folder stacked together.
So the whole job is a format change. Read the individual MDaemon message files, write them into MBOX containers, hand those containers to Thunderbird. No server connection needed for the conversion itself, because both formats are just files on disk.
That’s exactly what the converter below does in one run.
Can you do it manually over IMAP?
Yes, if the MDaemon server is still alive. Add the MDaemon account to Thunderbird over IMAP, let it sync fully, then drag everything into Local Folders so a copy survives after the account dies. Free and built in.
The honest limits. It needs the server running and reachable, which retired servers are not. Sync on a large mailbox can take hours and stall silently. It handles one account per setup. And dragging hundreds of nested folders by hand is exactly the kind of work where humans miss one.
One mailbox, server still online, plenty of patience. Go manual. Anything else, keep reading.
“I judge a converter by how boring the import is. Clean MBOX output drops into Thunderbird without drama. Malformed message separators are how one mailbox turns into three hundred empty messages, and you only find out after the source is gone.”
Shubham Dixit · Independent Expert, Email Forensics and Data File Conversion
How to convert MDaemon to Thunderbird format?
The PCDOTS Email Converter reads MDaemon files straight from a copied folder and writes Thunderbird ready MBOX output with the folder tree intact. The MDaemon server doesn’t need to be running. The same engine also ships as a dedicated MDaemon Converter if you want the single purpose tool.
Runs on Windows 11, 10, 8.1 and earlier. Free demo converts 10 emails per folder.
Six steps from MDaemon files to Thunderbird ready output.
Step 1: Install and launch the software
Download the setup on your Windows computer, install it and open the application.
Step 1: The Email Converter home screen after launch.
Step 2: Load your MDaemon files
Click Open, go to Email Servers and pick MDaemon Files. Browse to the copied MDaemon user folders.
Step 2: Choosing MDaemon Files from the Email Servers menu.
Step 3: Preview and select the emails
All folders load into the left panel with full message preview. Check the data, untick anything you don’t need and move on. This is your first integrity check before anything gets written.
Step 3: MDaemon folders loaded with full preview.
Step 4: Choose Thunderbird as the export option
Click Export and select Thunderbird from the saving options. The software writes the output as MBOX, which is Thunderbird’s native mailbox format.
Step 4: Picking Thunderbird from the export menu.
Step 5: Set the destination and save
Choose a local folder for the output and click Save. The conversion runs with live progress on screen and reports when every folder is done.
Step 5: Setting the destination and starting the conversion.
Step 6: Collect your Thunderbird ready files
Open the destination folder. Your MDaemon mailboxes now sit there as MBOX files in the original folder structure, ready for the import below.
Step 6: The converted output ready for Thunderbird.
How to import MBOX files into Thunderbird?
Here’s the step most guides skip. Thunderbird has no Import MBOX button on a fresh install, so use the free ImportExportTools NG add on. It takes 5 quick moves.
- In Thunderbird, open the menu, choose Add-ons and Themes and search for ImportExportTools NG.
- Install it and restart Thunderbird if asked.
- Right click Local Folders in the folder pane.
- Choose ImportExportTools NG, then Import mbox file.
- Select your converted MBOX files and watch the folders appear.
After the import, run a quick check. Compare folder counts against the converter’s output, open a few old messages and confirm the original dates survived. To peek inside any MBOX file without importing it at all, the free MBOX viewer opens them directly.
Manual IMAP method vs Email Converter
One table to settle it. Pick by mailbox count and server status.
| What matters | Manual IMAP method | PCDOTS Email Converter |
|---|---|---|
| Needs MDaemon server running | Yes | No, reads copied files |
| Multiple mailboxes in one run | No, one per setup | Yes, batch supported |
| Folder structure preserved | With careful dragging | Yes, automatic |
| Preview before transfer | No | Yes |
| Other output formats available | No | PST, PDF, EML, CSV and more |
| Cost | Free | Free demo, $99 full |
| Best for | 1 mailbox, live server | Batches and retired servers |
People also ask
How do I import MBOX files into Thunderbird?
Install the free ImportExportTools NG add on from Thunderbird’s Add-ons manager. Then right click Local Folders, choose ImportExportTools NG and pick Import mbox file. Select your MBOX files and Thunderbird loads them as regular folders.
Where does MDaemon store user emails?
MDaemon keeps each message as an individual plain text file inside per user folders on the server, normally under the MDaemon\Users directory. Copy those folders and you have everything the migration needs.
Do I need the MDaemon server running for the conversion?
No. The converter reads MDaemon files directly from a copied folder, so a retired server can be migrated from backup data. Only the manual IMAP method needs the server live.
Will my folder structure stay intact in Thunderbird?
Yes. The converter writes one MBOX file per MDaemon folder and keeps the tree layout, and ImportExportTools NG can import a whole directory structure in one go.
How many emails can I convert for free?
The free demo converts 10 emails per folder, enough to test the complete MDaemon to Thunderbird workflow on real data before buying. The licensed edition removes the cap.
Can the same software export MDaemon to other formats?
Yes. Besides Thunderbird MBOX, it exports MDaemon data to PST, PDF, HTML, CSV and EML, plus services like Gmail, Office 365 and IMAP. We covered the IMAP route in our MDaemon to Zimbra migration guide.
The short version
So moving MDaemon mails to Thunderbird is a 2 stage job. Convert the MDaemon files to MBOX, then import the MBOX into Thunderbird with ImportExportTools NG. The manual IMAP bridge works for a single mailbox on a live server, while the converter handles batches, retired servers and everything in between with previews along the way. Verify your folder counts at the end and the migration is done properly.
Run the free demo on one mailbox and see the whole flow before committing.
Which mailbox are you moving first?
