How to Convert EML Files to MSG on Windows and Mac OS?

  Rollins Duke
Rollins Duke   
Published: January 13th, 2026 • 8 Min Read

Do you want to convert EML to MSG? This guide offers the best solutions to easily convert EML files to MSG format. Many users have thousands of EML files exported from Windows Live Mail, Thunderbird, stored backup files or received from any other user. However, since users have switched to Outlook for its modern features, accessing these old EML files requires converting them into Outlook native MSG format.

While both are email file formats, both have different structures. EML uses the MIME format, whereas MSG uses Binary MAPI format. You cannot access an EML file in Outlook by renaming the .eml extension to .msg as it can corrupt the file. Moreover, using the Drag and Drop method it will consider your EML file as an attachment and batch drag and drop EML files can lead to freeze or crash of Outlook.

Why are DIY Methods Risky?

  • Manual Method often changes date modified timestamps to current date. In legal or forensic scenarios, this destroys the chain of custody.
  • Free online EML to MSG converters require you to upload EML files to a server, which means sharing your business confidential information with unknown people. This information can be used against you, shared with other people, or sold, and it can break your business privacy.
  • Many free solutions may fail to transfer embedded attachment and resulting in blank attachments.

How EML and MSG File Formats Differ from Each Other?

  • What is EML File Format: EML files are a standard email file format used by several email platforms like Thunderbird, Gmail, etc. This file format stores email content, sender and receiver email IDs, subject, date, email header, etc.
  • What is MSG File Format: MSG files are a proprietary file format developed by Microsoft to store a single email message containing all email data, including the header. It is primarily supported by MS Outlook and Exchange Server with advanced metadata and object handling capabilities.

EML Vs MSG File: What is the Major Difference?

Criteria EML MSG
File Format Plain Text MIME Format Binary Format
Compatibility Multiple Email Platforms Microsoft Outlook and Exchange Server Only
Developed By Microsoft + Internet Engineering Task Force (IETF) Microsoft
Best For Cross-Platform Sharing Outlook Specific Use

Reasons to Change EML File to MSG?

  • Compatibility: MSG files are more compatible with Microsoft Outlook because MSG files are the native email formats of Outlook. It also preserves formatting and includes attachments very well.
  • Accessibility: MSG files are easier to open and read for users who primarily use the Outlook application. This point is very important when it comes to converting an EML file to MSG.
  • Easy Backup and Archive: MSG files work better in systems that are Outlook-optimized for archiving and backup applications.

Note: Users can leverage MSG files for these advantages. Converting EML to MSG files is essential, especially if you use Microsoft Outlook for email management and communication.

Free and DIY Ways for EML to MSG Conversion

If you need to turn a small number of EML files to MSG and do not have confidential information, then you may choose 2 ways described below to overcome your problem if you are using Windows OS, then you may use the Outlook client to change EML to MSG format. Alternatively, for Mac OS, you may use the online converter available on the web. However, these free online EML to MSG converters often have EML data privacy concerns. Therefore, these tools are not suggested by experts.

How to Convert EML to MSG Using MS Outlook for Windows?

  1. Initially, go to the file explorer and locate your EML files for conversion.
  2. Next, right-click on the EML file and choose Open with > Outlook.
  3. Now, click on the File tab from the top-left corner and choose the Save As option.
  4. After that, define the name of the exported file and select the destination path.
  5. Lastly, click on the save button to convert EML to MSG using MS Outlook.

Turn EML into MSG on Mac and Windows OS Via Online EML to MSG Converter

  1. At the start, run any of the online EML to MSG converters.
  2. Next, add the EML files from your local storage for conversion.
  3. Thereafter, you need to generally click on the Convert button.
  4. Lastly, the online converter will provide EML to MSG format in your downloads folder in Windows and Mac OS.

Limitations of Choosing the Individual EML to MSG Conversion Way

  • The online converter to change EML to MSG format generally has a 25MB file size limitation for free conversion. For more, you need to pay for the excess, depending on the pricing policy of the online software provider.
  • Another major drawback of the online tools is that they process your data for EML to MSG conversion on the server side. Therefore, there is always a chance that your data might be sold or handed over to someone else for money.
  • The downside of using the Outlook email client is that you must repeat the same steps for turning each EML file into MSG format. This is a very time-consuming process and always has the chance of human error during the conversion process.
  • The free approach is only suitable for users who need to convert a few EML files to MSG, like three to five, and do not handle crucial data in EML files. If these conditions do not apply to you. Then it is not suggested by experts to choose free or DIY approaches.

Pro Solution to Batch Convert EML to MSG Format

If you need to overcome all the above-described solutions for converting EML to MSG, then you may choose a reliable and offline solution such as BitRecover EML Converter. This solution is specially designed to batch convert EML files to MSG format at once in offline mode. Additionally, this solution is equipped with several filter settings to selectively convert EML to MSG format from multiple files at once. You can try the free version of this desktop-based tool on both Mac and Windows OS to test its out-of-the-box functionalities and capabilities. To know the working of this simple utility, please walk through the steps described below.

How to Transform EML to MSG File Format? Stepwise Tutorial
  1. At the start, download and run the BitRecover EML to MSG Converter on your PC.
    open EML to MSG Converter
  2. Next, tap on the Select Files or Select Folders option to load EML files for conversion.
    click select files or folders
  3. After that, enable the folder of EML files you need to transform to MSG format.
    enable required files or folders
  4. Thereafter, choose the Saving option as MSG from the drop-down list.
    choose the saving option as MSG
  5. Now, choose the destination path and naming format for converted MSG files.
    choose destination path
  6. Then, for advanced selective EML to MSG conversion, click on Filter options and apply accordingly.
    filter settings
  7. Finally, tap on the convert button to change EML to MSG format in batch mode.
    EML to MSG
Online EML to MSG Converter Vs Offline Software Vs Free Ways: Quick Comparison
Criteria Online EML to MSG Converter Desktop-Based Offline EML to MSG Converter Free DIY Ways to Change EML into MSG Format
Speed EML to MSG processing speed is directly proportional to the speed of the internet connection. Fast with the ability to process multiple files in one go. Slow, it can process only one EML file at a time.
EML Size Limit Commonly limited to 25 MB No file size limitation No size restrictions
Data Privacy Data privacy might be breached. Since the EML to MSG file conversion is done on remote servers. 100% Data security assurance. All the EML to MSG processing is done on your local machine in offline mode. 100% Data privacy, but users need to manually handle the EML files for conversion to MSG format.
Batch Processing Often available in some tools and sometimes locked for the paid version. Supports secure and fast EML to MSG bulk conversion. Batch EML to MSG conversion is not supported.
Cost Free for small files, but paid for large files Paid EML to MSG converter with a free trial edition Completely Free
Reliability May fail for big or complex files. Highly reliable Prone to mistakes
Platform Windows and Mac OS Windows and Mac OS Windows OS
Concluding Thoughts

In this guide, we have discussed about how to convert EML to MSG and provided a quick comparison. Secondly, we have seen the free and DIY ways to save EML files as MSG. However, these methods have many drawbacks and fail to maintain privacy. Therefore, we have shared the best EML to MSG Converter to overcome the limitations of free and online tools. After using this tool, users can convert any number of EML files, and finally, you will be familiar with the options after seeing the comparison of the three methods based on specific criteria.


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