Making email migration an easy ride ™ - time after time!

How to transfer emails from Thunderbird to Outlook?

How to transfer emails from Thunderbird to Outlook?

Thunderbird to Outlook Transfer – User’s Manual

Thunderbird to Outlook Transfer iconThis user’s manual covers the process of converting and transferring emails and attachments from Thunderbird to Outlook. Due to the difference in data formats used by these programs and their general approach to storing data, direct import with integrated tools or functions is impossible, and such migrations require the use of specialized conversion software like Thunderbird to Outlook Transfer. The program automates nearly 99% of the process, but still requires some user involvement, and the article below describes it in detail.

Content of this instruction:

File and folder selection

All our products are designed to automatically detect the location of the source data files of corresponding programs. However, this is not always possible. If Thunderbird to Outlook Transfer utility fails to detect the path to *.msf data files and mailing list automatically, this may be a sign of conflicting profiles, identities, a registry corruption issue or another minor issue rendering path auto-detection impossible. It will also happen in situations when you have multiple Identities or Thunderbird data files are copied from another system – that is, when Thunderbird has never been installed on the user’s system.

In case the program fails to locate your *.msf emails automatically, click the “…” (Browse) button to open the standard Windows folder selection dialog and select the source folder manually. By default, Thunderbird stores emails in a profile folder located here:

C:\Documents and Settings\%USERPROFILE%\Application Data\Thunderbird\Profiles\XXXXXXXX.default\Mail\

Where %USERPROFILE% is your username, and XXXXXXXX is a sequence of arbitrary characters.

Please note that the “Application Data” folder is hidden by default and will not be visible in the dialog.

To make hidden folders visible, do the following:

  • Open Windows Explorer (Ctrl+E) , click on “Organize” and select the “Folder and Search Options” command from the menu.
  • Switch to the “View” tab
  • In “Advanced settings”, find the “Hidden files and folders” node and expand it
  • Enable the “Show hidden files and folders” radio button
  • Uncheck the “Hide protected operating system files” option
  • Click OK.

Doing this will unhide hidden folders and allow you to select the one containing Thunderbird source files in the manual mode.

IMPORTANT: Please bear in mind that Thunderbird to Outlook Transfer tool is capable to detect the main Thunderbird profile location automatically if Thunderbird email client is installed at the same system. However Thunderbird profile may contain several Identities and Account records. In this case it is required to select the proper source directory manually. For multi Identity configuration we recommend to process each email account separately. Thunderbird to Outlook Transfer program can extract and convert data from damaged mailbox files of all supported formats and import them in to 2010, 2016, 2019 an earlier versions of MS Outlook.

While working on Thunderbird to Outlook Transfer application, we pursued the goal of automating as many complex operations as possible, and we’ve got most of the process covered by our tool. Your role is restricted to making a couple of simple choices and confirming your selections. You have three options: direct import to Outlook, saving messages to a new standalone PST file, or extraction of Thunderbird mail to EML files The first scenario is fairly self-explanatory, while the second and third allows you to copy the resulting file(s) to any type of drive or cloud storage or transfer it to another system.

Alternative Scenario

If you still have the Mozilla Thunderbird installed at your computer, you may use menu Options | Account Settings | Server Settings to check the location of the email message store. The value of field “Local Directory:” is what you need.

Location of Thunderbird message store

Prior to start the conversion

When you delete or move messages from one Thunderbird folder to another the source mailbox file remains unchanged as the original message is simply marked as deleted or moved and became hidden from view. In order to correct the message indexing and optimize space occupied by the mailbox files we recommend to “compact” Thunderbird folders before you start the conversion.

  • To compact a single folder, right-click on the Thunderbird folder name and select Compact.
  • To compact all folders, select menu File > Compact Folders.

Compaction progress will be shown in the status bar.

Important! Exit Thunderbird email client prior to run the Thunderbird to Outlook conversion procedure. Thunderbird may block one of mailboxes data files and this will cause the share violation error during conversion.

Saving emails from Thunderbird to a standalone PST file on your hard drive

If you want to convert Thunderbird emails to the PST format i.e. convert *.msf to *.pst, but don’t want to export them to Outlook right away, you can save them to a PST file on your HDD for future use of copying to another computer. Please note that Thunderbird to Outlook Transfer software will still require Microsoft Outlook to be installed on your system in order to create this PST file.

To do that, follow these simple steps:

  1. Download and install the latest version of Thunderbird to Outlook Transfer tool on your PC. Installation normally takes less than a minute and does not require any additional components or libraries to be downloaded.
  2. Run Thunderbird email conversion tool. If your Outlook edition is 32-bit, you have to use the shortcut which launches 32-bit conversion utility, otherwise you have to run the 64-bit tool. Both shortcuts became available at your computer after the installation.
    Thunderbird Transfer icons
  3. The program should automatically detect the location of the source *.msf and mailbox files. If it doesn’t, click on the “…” (Browse) button and select the necessary folder on the hard drive (see “File and folder selection” for details). The same can be done using the File->Open command.
    Use browse button to select the Thunderbird message store
  4. Click “Scan Folder” button, the program will show a list of available folders (email containers) in the large text area in the center of the program window. You may deselect there a folder(s) which you do not want to be processed, for example to skip the Inbox emails, yo may uncheck the Inbox container.
    Thunderbird email folders will be shown
  5. Use menu Mode to enable “Save to PST File” mode.
  6. Exit Thunderbird if it is still launched. Click on “Save“. The program will prompt you for a folder that the resulting PST file will be saved to.
  7. Select the location to save PST file and confirm the saving.
    The program will create the copy of Thunderbird folders in Outlook and transfer emails accordingly
  8. Wait until the program has finished processing all the files. Full details about the items being processed will be provided in the log window.

The resulting PST file can be immediately copied to another system and loaded to Microsoft Outlook using menu File -> Open -> Outlook Data File…

If Thunderbird is not installed on your system, you can still use Thunderbird to Outlook Transfer software. Just copy the Thunderbird data folder from any other system and convert its contents into a PST file. Copy the PST file to the destination system and load it in Outlook to access the converted emails.

Direct transfer of emails and attachments from Thunderbird to Outlook

Imagine that you have Thunderbird and Microsoft Outlook installed on the same system or that you have Outlook and some Thunderbird data files copied from another computer.

Here is what you need to do to transfer your data:

  1. Download and install the latest version of Thunderbird to Outlook Transfer program on your PC. Installation is fast and easy, and does not require any additional tools to be downloaded.
  2. Run Thunderbird to Outlook Transfer tool. (Use the proper edition for your Outlook type)
    Choose 32 bit or 64 bit icon
  3. The program should automatically detect the location of the source files. If it doesn’t, click on “…” (Browse) and navigate to the necessary folder on the hard drive (see “File and folder selection” for details). The same can be accomplished using the File->Open command.
    Thunderbird source selection
  4. Once you have selected a folder and its name has appeared in the Source Folder field, click on “Scan Folder” or use the File->Scan Folder command to start searching for mailbox files in the specified folder. The names of available Thunderbird mailboxes will be shown in the large text field occupying the central part of the program window.
    Find emails and folder in Thunderbird store
  5. Click “Import” to start importing your messages. A new dialog will pop up and prompt you for the destination Outlook folder that your imported messages will be saved to. Full details about processed items are shown in the log window.
    Process of Thunderbird emails and folders conversion
  6. Once the process is over, you can launch Outlook to access your messages.

Thunderbird to Outlook Transfer helps move your emails and attachments from one application to another in virtually no time.

Should you have any problems converting your emails using our product, please contact our support team with a description of your problem, and we will do our best to get back to you as soon as possible.

Other Tutorials


IncrediMail to Thunderbird

IncrediMail to Outlook Transfer software allows to export IncrediMail emails to individual files of EML Read more


IncrediMail to OE Classic

IncrediMail to Outlook Transfer can also be used to migrate to other email clients which Read more

Mailbird logo

IncrediMail to Mailbird Migration

Mailbird is modern messaging application which allows to use multiple accounts to manage emails, supports Read more

Windows 10 Contacts

How to Import .contact Files into Outlook

Initially, Microsoft Windows used the WAB application (Windows Address Book) to store the contact information, Read more

Roundcube Logo

Conversion from Roundcube to Outlook

Roundcube is free open-source email software for web. It widely used by webhosting companies worldwide Read more

How useful was this article?

Click on a star to rate it!

Average rating 3.7 / 5. Vote count: 9

No votes so far! Be the first to rate this post.

As you found this post useful...

Follow us on social media!

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?


After reading this instruction I have only one question now – how to convert also my Thunderbird address book to Outlook contacts?

Looks good, but Ii also need to export an old email account to outlook (I can’t set it up as I have forgotten the password and no longer deal with the original supplier of the email account, although I still get emails for this account)
Can you help please?

Hi, Alan, there is not enough information unfortunately to guess something, please drop us a letter via the contact form, we will try to help you.

Hi Gordon
Thanks for the reply but I have resolved my issue.


How to transfer emails from Thunderbird to Outlook?

time to read: 6 min