When we talk about email and their respective email clients, we cannot deny that Outlook is one of the most famous and highly preferred email clients for Windows as well as Mac OS. Besides, it is considered as the best email client for businesses, corporates, organizations, and individuals, who handling more than 100 emails a day.

Although MS Outlook is also versioned for the Mac platform, sometimes Mac users need to convert their PST file to MBOX. But what makes Mac users convert their Outlook PST file into MBOX.

Reasons why you need to convert PST to MBOX

Given below are most common reasons to state why you may need to convert or import Outlook PST files to Mozilla Thunderbird (MBOX) format supported by different email clients like Apple Mail, Eudora, SeaMonkey, Netscape, Evolution, Spice bird and more.

  • MS Outlook becomes expensive for many normal users in the long run as after a point of time they need to buy the licensed version of MS Office. Desktop email clients that are available either as open source or for free on the web are quite preferred by single users.
  • PST files become corrupt and may become inaccessible in MS Outlook. When we speak on Microsoft products, the native methods to fix corruption or damage aren't much efficient, and PSTs are bound to work only with Outlook. Thus, if the file corrupts for once, you’ll be stuck for long.
  • Outlook users have to stick with Windows OS, whereas MBOX files can be accessed on any OS including Windows, MacOS, Linux, etc.
Comparison between PST and MBOX file
Features PST (Personal Storage Table) MBOX (Mailbox File)
Operating System It's accessible on all versions of the Windows operating system. You can open it on any system running with Windows, MacOS, and even Linux (including distros).
  • PST files are accessible only in MS Outlook. Also, you can import these files to Microsoft platforms like MS Exchange Server, Office 365, and Outlook for Mac.
  • You can use free applications like Kernel PST Viewer to view PST emails.
  • MBOX format is used by email clients such as Thunderbird, Apple Mail, Eudora, Entourage, Postbox, PocoMail, Netscape, Spicebird, Claws Mail, Opera, PowerMail, Sylpheed, Evolution, SeaMonkey, Mulberry, GyazMail, Sparrow, Gnu, and The Bat. Gmail also creates email backups in MBOX format.
  • Also, you can use free applications like Kernel MBOX Viewer to view MBOX emails.
Cost Outlook is not made available for free. You’ll have to buy a license to continue using it.


You can download any Linux distro and install Mozilla Thunderbird on your system to open the MBOX file, without really spending anything.


Now, that you know and understand why and when someone might need to convert or import the Outlook PST data file to MBOX (Mailbox file), and the basic differences between the two file formats, next comes, how you can convert the PST file to MBOX?

Methods to convert PST file to MBOX

This section explores the two most popular ways of converting a PST file to MBOX without creating any hassle for the users.

Convert PST to MBOX file manually?

The manual method of converting PST files includes first establishing Outlook as a default email client. Once it’s found, follow the given steps to convert to MBOX file.

  1. Go to Control Panel>Default Programs>Set your default programs and then select Outlook to set as default program.
  2. Click OK to make Outlook as your default email application.
  3. Launch Outlook on your system and check if the data you’re planning to transfer is available there.
  4. If the data is not there, import it using PST file.
  5. Now, open Mozilla Thunderbird and go to Tools and click on Import option.
  6. Choose Mail and click Next.
  7. Select Outlook from the list of email clients and then Next.
  8. Close the Import wizard.

Once you export PST files to Thunderbird, it’s time to move the data to Thunderbird in MBOX format.

  1. Launch Thunderbird and then install the ImportExportTools NG add-on.
  2. Select Tools then ImportExportTools and click Export all the folders.
  3. Define the location to save the file
  4. Click Select Folder and your PST files are converted to MBOX.

Even though this method is quite effective, it is supported by the limited versions of Outlook and if any of the steps is missed, it can eventually lead to data loss. Therefore, make sure that you are cautious before proceeding with this method. However, to avoid complications, one can proceed with the professional solution for converting files.

Converting PST files with professional solution

To perform Outlook PST to MBOX (Mozilla Thunderbird) file conversion, we'd suggest using Kernel for Outlook PST Repair, an advanced tool created to handle all sorts of issues or needs associated with Outlook PST data file.

To perform Outlook PST to MBOX (Mozilla Thunderbird) file conversion, you can find many efficient methods supporting a seamless process. However, we'd suggest using convert the repaired PST files into MBOX and other different file formats. Here, we'll show you how to convert a PST file to MBOX with Kernel for Outlook PST tool.

  1. Download PST to MBOX converter tool and install on your system.
  2. On launching the tool, a welcome window will appear on the screen. launching the tool
  3. Browse the file that you want to recover/repair and click "Next," click Next Note: From this section, you can also add multiple PST files to convert to desired format.
  4. In the next step, read the information and click "Finish" to start the repairing process. start the repairing process
  5. Once the repairing process is complete, you'll be able to see the folders containing the PST files. Click any folder to preview its emails/items in the tool. Click any folder to preview its emails/items in the tool Note: You can also preview email attachments from here by double-clicking the attachment.
  6. Now, to save this file into MBOX format, click the Save button from the upper left corner of the tool. Select "MBOX file" from the opened window and click "Next".  click Next
  7. In the next step, select the specific filters that you want to apply to the PST file and click "Next." apply to the PST file
  8. Now, select the Email client for the MBOX file, and specify the location where you want to save the MBOX file. Click "Finish" to complete the process, Click Finish Note: If you want to exclude the deleted items from the file, then check the checkbox "Exclude deleted items."
  9. A notification wizard will appear on your screen displaying "Items has been saved successfully," click "Ok" to close the process. click Ok to close the process This way you can quickly repair a PST file and convert PST to MBOX file.

Final Words

Converting PST to MBOX becomes a necessity when you want to access your Outlook email data over Mac email clients. But the manual conversion process will take you through a lot of ups and downs if the PST file is damaged or corrupt and you don’t know the right technique for it. In this article, we discussed how you can transfer your Outlook PST data to MBOX file format using Kernel for Outlook PST Repair, which first repairs the corrupt PST file and then converts it to MBOX and other file formats.