Convert MSG to EML Files: Manual, Scripting & Bulk Methods

It is possible to convert MSG files (Outlook’s proprietary email message format) to EML files, which are plain-text, MIME-based formats supported by multiple email clients, including Thunderbird, New Outlook, and Zoho.

You can convert MSG files to EML files using 3 approaches — a free manual approach using Outlook Classic, a developer approach using scripts, or a purpose-built tool available to save MSG files to EML with a GUI interface offered by trusted vendors.

Expert Advice: In case you want to go for a third-party vendor to export Outlook MSG files to EML files — use an offline one, as although the online ones seem to make the task easier & quicker — your data is always at risk of a breach.

How are MSG Files Different From EML Files?

Both MSG and EML files are formatted, but they vary significantly on the basis of their storage architecture. Thus, you cannot simply convert MSG files to EML files by changing the extension or via the common techniques.

An MSG file is a binary OLE compound document file format produced by Microsoft Outlook. It contains a single e-mail message, including all headers, body, and attachments, in a single proprietary file.

An EML file is a plain text file that adheres to the MIME (Multipurpose Internet Mail Extensions) standard. It contains the same email data as MSG, but in a readable, cross-platform format that clients like Thunderbird, Apple Mail, and most webmail import tools can open directly.

Why Convert MSG Files to EML? – User Need Where This Guide is Helpful

• Cross-client migration: Accessing legacy MSG data archived from Outlook in another email client.
• Compliance Bases Long Term Archiving: EML is a plain text, non-proprietary format that is less tied to a single software vendor. It is also often required by eDiscovery and email-review platforms.
• Server-side compatibility: Most IMAP servers and open-source mail tools read EML natively

Method 1: Convert MSG to EML Manually using Outlook (Free)

Prerequisite: Outlook New – Free Application

Note. The conversion using Outlook from MSG to EML only works for Windows computers.

1. Open Outlook New on your Windows computer.
2. Right-click on the MSG file in File Explorer and open with Outlook.
3. Open the MSG email content, click on … (more option).
4. Go to Download >> “Save as EML”.

Limitation: It is a manual and file by file approach. For more than a handful of messages or when folder structure and metadata must be preserved exactly across a full mailbox, this is impractical.

Method 2: Convert MSG to EML using a script (for developers)

Developers can automate MSG-to-EML conversion using scripting libraries that parse the MSG compound-file structure and reconstruct the message as MIME-formatted EML output. This approach is commonly used in:

• Automated pipelines that process email exports as part of a larger workflow
• Environments where a GUI tool cannot be installed (headless servers, CI pipelines)

Limitation: Requires programming knowledge, and script-based parsing can mishandle edge cases like unusual character encodings, embedded OLE objects, or corrupted MSG headers unless the script is actively maintained and tested against real-world files.

Method 3: Convert MSG to EML with BitRecover Solution

BitRecover MSG to EML Converter lets you bulk convert MSG files and folders to EML while maintaining the exact folder hierarchy. It offers multiple file naming options, making it easy to locate the exact EML file you need later. The tool supports both classic MSG files and the latest MSG versions, ensuring seamless conversion across formats. It retains complete email data, including attachments, header information, CC, BCC, date, timestamp, signatures, and other email properties. All attachments are embedded within the output EML files, and the generated EML files are compatible with multiple email clients and platforms for easy importing. The entire conversion process is 100% offline, so your email data never leaves your computer, and there is no risk of a data breach. No internet connection is required to perform the conversion. The tool is HIPAA, GDPR, and SOC 2 compliant, making it suitable for handling sensitive email data. It is extremely easy to use, supports bulk processing, and comes without any mailbox size limitation, allowing you to convert large volumes of MSG files efficiently.

You can also get the free version of the tool for Windows, which lets you convert up to 25 MSG files per folder to EML completely free of cost.

FAQs

Does converting MSG to EML remove any data from the original file?

No — conversion creates a new EML file; the source MSG file is left unedited. Reputable conversion methods work on a copy of the data rather than modifying the original.

Can EML files be opened in Outlook after conversion?

Outlook does not natively open EML files by double-clicking in all versions; some versions require an add-in, or the file can be dragged into an existing Outlook folder. Thunderbird, Apple Mail, and most webmail import tools open EML files directly.

Is there a size limit on how many MSG files can be converted at once?

This depends on the method: manual Thunderbird conversion has no built-in batch limit but must be done one file at a time; the BitRecover MSG to EML Converter free trial is limited to 25 items per folder, with no limitation in the licensed version.