How to Convert EML to MBOX in Bulk? Updated 2026 Guide

Feature	EML File	MBOX File
File Structure	Store single email messages	Store multiple email messages in a single file
Management	Difficult, especially in cases where a user have large volume of data	Easy, as all the emails will be stored at a single location in one file
Backup	Requires time in copying each file	Can be done faster as compared to in EML file
Use Case	Suitable for sharing or saving individual email messages	Used to archive or share an entire mailbox data with seamless management
Risk of Corruption	Low. Only one file will get affected, rest of the files will be saved	High. Entire folder will get affected
Storage Method	EML files store single emails with attachments and other data	Emails are stored in a single database like a mailbox file

Reasons to Convert EML to MBOX

• MBOX files are easy to manage than managing thousands of EML files.
• Many email clients store emails in MBOX format so converting EML files allows importing emails easily without any compatibility issues.
• Searching emails from a heap of EML files is a bit difficult. Whereas, storing them in a single MBOX file is much easier to locate and manage.
• Converting EML to MBOX allows users to create a single file that is easier to store for long term backups.

Things to Remember Before Transferring EML files

Before performing EML to MBOX conversion, make sure you have followed these steps:

• Create backup of EML files
• Collect and organize all EML files in a single folder.
• Ensure you have enough storage space.
• Check if any file is corrupted or not.
• Remove duplicate EML files to avoid confusion and enjoy a fast process.

Quick Overview: How to Convert EML to MBOX?

There are three approaches to transfer EML files to MBOX i.e. manual method for Windows, a manual method for Mac and an automated solution. We have explained each method with proper and updated steps.

On Windows, you are required to have Thunderbird installed and on Mac, Apple Mail is required. While these manual ways are reliable and can work but they have multiple complex steps. So, to simplify this process, a professional solution is recommended as it converts multiple EML files at once while saving time and preserving all the email properties.

How to Convert EML Files to MBOX Manually?

Here we are going to discuss manual ways for both Windows and Mac systems.

Method 1- Transfer EML to MBOX via Thunderbird

Phase1- Install the Add-on

1. Open Thunderbird on your system.
   
2. Go to the main menu > Add-ons and Themes option.
   
3. Write ImportExportToolsNG in the search bar and click on the Add to Thunderbird button.
   
4. After that, simply restart Thunderbird.

Phase2- Import EML to Thunderbird

1. Right click on a folder under your configured email ID.
2. Select New Folder and enter a name as per your choice.
3. Now, right-click on the newly created folder > press ImportExportToolsNG option > Import EML messages and then Individual EML Messages.
   
   
4. After that, you will see a pop-up, simply select all the required EML files from local drive.
5. Lastly, click on Open.

Phase3- Convert EML to MBOX

1. Once you have imported all the EML files in Thunderbird.
2. Again right-click on that particular folder and select ImportExportToolsNG option.
3. Now from the list, choose Folder Export (mbox) > As mbox file.
4. Select a destination folder to store MBOX mailbox and click Select Folder.
5. To check, go to the desired location and access your MBOX file.

Note: The saved file will be a MBOX file but without the .mbox extension, so don’t get confused.

Limitations:

• Requires installation of Thunderbird email client.
• This method has many complex steps which can be confusing for a beginner user.
• It is a time-consuming and lengthy process.
• It can slow down Thunderbird if multiple files are imported.

Method 2- Convert EML files to MBOX using Apple Mail

1. Open Apple Mail on your system.
2. Under the On My Mac section, create a new folder to import EML files.
3. After that, go to the location where EML files are saved.
4. Select files > right-click > Open with > Mail.
5. Move or drag these emails in the newly created folder in Apple Mail.
6. Now, right-click on the folder > select Export Mailbox.
7. Choose the destination to store the resultant files.
8. That’s it, your MBOX file will be automatically saved on the system.

Limitations:

• Apple mail imports EML files individually which can make the process more long and time-consuming.
• The original folder structure may get affected during the process.
• It is not a suitable method for bulk converting EML files to MBOX.

Core Features of the EML to MBOX Converter

• It offers dual file selection modes to convert both single EML files as well as entire folders.
• The tool guarantees to maintain all email properties such as To, From, CC, BCC, Subject, Attachments etc throughout the process.
• Provide 100% accurate and perfect results in just a few minutes.
• Plus, it supports all types of EML files created from any email client.
• Using this software, users can batch convert EML to MBOX in a single cycle without any data loss.
• This utility has the ability to convert even large size files smoothly as it does not impose any restrictions.
• It is a completely standalone solution that performs conversion without requiring installation of any email client.
• Fully compatible with all versions of Windows and macOS even if you are working on old editions.

How to Convert EML Files to MBOX Quickly? Steps

1. Download and install the EML to MBOX Converter.

   

2. Load EML files or folders that you want to convert.

   

3. Check or uncheck the selected files to avoid unnecessary emails.

   

4. Now, choose MBOX from the list of saving options.

   

5. Set the advanced filters from the Filter Options tab, as per your needs.

   

6. Browse a destination path to store the resultant MBOX file.

   

7. Lastly, click on Next to start the EML to MBOX conversion process.

   

Compare Manual Methods vs Automated Tool

Conclusion

I hope by the end of this article, you have got the right method to convert EML to MBOX. While there are manual methods as well but they hold multiple drawbacks and involve risk, so choosing the professional solution is a smart move. It will protect your data and will convert files in a few minutes while saving your valuable time. Additionally, if you face any query related to the tool, then you can directly contact the support team either via Live Chat or email on [email protected]. We are 24/7 available to assist your queries.