Written by Jennifer Walsh. Reviewed for technical accuracy by Shubham Dixit, Independent Expert in Email Forensics and Data File Conversion.
Shubham is an independent external reviewer and not an employee of PCDOTS.
Quick answer. Thunderbird keeps your mail internally as MBOX, but it exports individual emails to EML for free. Drag messages from Thunderbird to a folder to save them as .eml, or use the free ImportExportTools NG add-on to export a whole folder to EML in bulk. A converter helps only when you cannot open Thunderbird, or have many folders to do at once.
On this page
MBOX inside, EML out
One thing clears up a lot of confusion here. Inside your profile, Thunderbird does not store each email as its own file, it keeps a whole folder in a single MBOX file. So there is no folder of .eml files sitting on your disk to copy. What Thunderbird does give you is an export, it can write individual messages out as EML whenever you ask, and that is exactly what the routes below do.
The good news is the export is free and built in. For a few emails you drag them out, for a whole folder you use a free add-on, and only the awkward cases need a converter.
A folder lives as one MBOX inside Thunderbird, and exports out as individual EML files.
“Thunderbird is one of those cases where the free route is genuinely the good route. Selecting messages and dragging them to a folder gives you clean EML files, and for a full folder the ImportExportTools NG add-on does the whole thing at once, also free. I only reach for a converter when there is no Thunderbird to open, someone hands me a copied profile or a loose MBOX, or when it is many folders and accounts together. For your own running Thunderbird, use its own export.” Shubham Dixit, Data Migration reviewer (draft, pending approval)
A few emails, drag them out
For a handful of messages this is the quickest thing there is, and it needs no add-on. In Thunderbird, select the emails you want, one or many with Ctrl or Shift, then drag them onto a folder on your desktop. Thunderbird writes each one out as a .eml file. You can also right-click the selection and choose Save As to do the same thing. It is instant for a few emails, and each file is a complete message with its attachments and headers.
A whole folder, ImportExportTools NG
When you want an entire folder as EML, the free ImportExportTools NG add-on is the tool for the job, and it is the piece the quick drag method cannot match.
Install it from Thunderbird’s Add-ons manager. Then right-click the folder, open ImportExportTools NG, and choose Export all messages in the folder, then EML format. It writes every message in that folder to a folder of .eml files in one go, and it can name them and keep subfolders as it goes. This is the free way to do hundreds of emails at once, and for most people it is where this task ends.
Drag for a few, the add-on for a whole folder, both free and native.
No Thunderbird open, a converter
A converter earns its place in the cases the free routes cannot reach, when you only have a copied profile or a loose MBOX and no running Thunderbird, when a profile is orphaned, or when you are exporting many folders, profiles or accounts together. The PCDOTS Thunderbird Converter reads Thunderbird’s files directly and writes the messages out as EML in bulk, with a search to pick out particular emails and options for how the files are saved. It runs on Windows and does not need Thunderbird installed. A free version handles the first ten items per folder so you can test it first.
The tool route, for a copied profile or many folders without opening Thunderbird.
Here are the steps with the screens.
Step 1. Install and run the software on Windows, then open the menu.
Step 2. Choose Email Data Files, Thunderbird, and load the files.
Step 3. Open the Export menu and select EML.
Step 4. Choose a destination folder and Save.
For related jobs see our guides to convert MBOX files to EML, since a Thunderbird folder is an MBOX, and import MBOX into Thunderbird.
Going the other way, EML into Thunderbird
Some people arrive here wanting the reverse, to bring EML files into Thunderbird. That works too, and it is also free. You can drag .eml files into a Thunderbird folder, or use the same ImportExportTools NG add-on to import all the EML from a directory at once. For the full walkthrough see our guide to import EML files into Mozilla Thunderbird.
And if you actually wanted plain text rather than EML, note that an EML file is already plain text under the hood, so you can open one in any text editor. ImportExportTools NG can also export as plain text or HTML if you prefer those.
The methods compared
Match the route to how many emails you have and whether Thunderbird is open.
| Method | Best for | Good to know |
|---|---|---|
| Drag or Save As | A few emails, free | Instant, no add-on |
| ImportExportTools NG | A whole folder, free | Bulk, keeps subfolders |
| Thunderbird Converter | No Thunderbird, or many at once | Windows, reads the files direct |
Frequently asked questions
Does Thunderbird store emails as EML files?
No. Thunderbird keeps each folder as a single MBOX file inside your profile. It exports individual messages as EML when you drag them out or use an add-on.
How do I convert Thunderbird emails to EML for free?
Select the messages and drag them to a folder, and they save as .eml. For a whole folder, use the free ImportExportTools NG add-on to export it to EML at once.
How do I export an entire Thunderbird folder to EML?
Install ImportExportTools NG, right-click the folder, choose Export all messages in the folder, then EML format. It writes every message to a folder of .eml files.
When do I need a converter instead?
When you only have a copied profile or a loose MBOX with no Thunderbird to open, a profile is orphaned, or you are exporting many folders or accounts together.
Can I import EML files back into Thunderbird?
Yes. Drag the .eml files into a Thunderbird folder, or use ImportExportTools NG to import all the EML from a directory in one step.
Do the EML files keep attachments and formatting?
Yes. An EML file holds the complete message, its headers, body and attachments, so nothing is lost in the export.
Turn your Thunderbird folder into EML files
You have everything you need to do this now. If it is a few emails, open Thunderbird, select them, and drag them to a folder, the .eml files appear at once. If it is a whole folder, add ImportExportTools NG and export the folder to EML in a single step, still free. Keep a converter in mind only for the cases the free routes cannot reach, a copied profile with no Thunderbird, or many folders and accounts together. So open your folder, pick your messages, and export them to EML.
