An EML file stores a single email message in plain text format

An EML file is a text document that contains one complete email — the message itself, the sender's address, the recipient's address, the subject line, and any attachments encoded inside it. The ".eml" extension stands for "electronic mail". When you export an email from Outlook, Gmail, Thunderbird, or most other email programs, you get an EML file.

The file is readable by humans if you open it in a text editor, though it will look messy because attachments are encoded as long strings of characters. The point of EML files is portability: you can save emails outside your email program, move them between computers, or switch email programs without losing them.

EML files are different from the email program's own format. Outlook uses .pst or .ost files to store many emails at once. Gmail doesn't create files at all — it keeps everything on Google's servers. But when you need to save one email or a few emails as standalone files, EML is the standard format across almost all email programs.

Key Takeaways

  • An EML file contains a single email message with headers, body text, and encoded attachments, saved as a portable text file.
  • You can open an EML file in any text editor, your email program, or a web browser, though a text editor will show the raw formatting.
  • Most email programs let you export individual emails as EML files through a right-click menu or File menu option.
  • EML files are useful when you need to move emails between different email programs or save them outside your email account.

How to open an EML file on Windows

The simplest way is to double-click the EML file. Windows will open it in your default email program if you have one installed — usually Outlook, Thunderbird, or Windows Mail. The email will display as it was meant to look, with the message body, attachments, and all formatting intact.

If double-clicking doesn't work, or if you don't have an email program installed, right-click the EML file and select "Open with". You'll see a list of programs. Choose Notepad or any text editor to see the raw file contents, or choose your email program from the list if it appears. If your email program isn't listed, select "Look for another app on this PC" and navigate to the program's folder manually.

You can also drag and drop an EML file directly into Outlook or Thunderbird. Open the program, then drag the file from File Explorer into your inbox or a folder. The email will import as a new message in that folder.

How to open an EML file on Mac

Double-click the EML file. Mac will open it in Mail, which is the default email program on most Macs. The email will display normally with all formatting and attachments visible.

If you don't use Mail, or if the file doesn't open, right-click the EML file and select "Open With". Choose your email program from the list — Thunderbird, Outlook for Mac, or another email client. If your program isn't listed, select "Other" and navigate to the Applications folder to find it.

You can also open the file in a text editor like TextEdit to see the raw contents. Right-click the EML file, select "Open With", then choose TextEdit. The file will display as plain text with all the email headers and encoded data visible — useful if you need to check the email's technical details or verify that an attachment is actually inside the file.

How to export an email as an EML file

In Outlook (Windows), right-click the email in your inbox and select "Save As". Choose a location on your computer, make sure the file type is set to "Outlook Message Format - Unicode (.msg)" or "Message Format (.eml)", and click Save. The .eml option will create a portable file; .msg is Outlook's own format and won't open in other email programs as easily.

In Gmail, you cannot export emails directly from the web interface. You must use Google Takeout (takeout.google.com), select Mail, and read your emails. Google will create a .mbox file, which contains many emails. You can then use a free converter tool to split the .mbox file into individual EML files, or import the .mbox file directly into Thunderbird or Outlook.

In Thunderbird, right-click the email and select "Save As". Choose a location and the file will save as an EML file automatically. In Apple Mail, drag the email from your inbox to your desktop or a folder — Mac will create an .eml file. In Outlook for Mac, right-click the email, select "Save As", and choose a location; the file saves as .eml by default.

Why you might need an EML file

The most common reason is switching email programs. If you're moving from Outlook to Thunderbird, or from one email provider to another, exporting important emails as EML files lets you import them into the new program without losing them. Email programs can usually import EML files even if they can't read each other's native formats.

You might also need an EML file to back up important emails outside your email account. If your email account gets hacked or deleted, or if you're leaving a job and want to keep copies of work emails, saving them as EML files on your computer or an external drive protects them. EML files are also useful for sharing a specific email with someone — you can send the file itself rather than forwarding the email through your email program.

Occasionally, you'll need an EML file for legal or compliance reasons. Some organizations require employees to save certain emails as files for record-keeping. EML files are a standard format that courts and auditors recognize.

What happens if you open an EML file in a text editor

You'll see the email's raw structure, including headers like "From:", "To:", "Subject:", "Date:", and "Content-Type:". Below that is the message body, followed by any attachments encoded as long strings of characters (usually in Base64 format, which looks like random letters and numbers).

This view is useful if you need to check technical details — for example, to verify the actual sender's address (which can be different from the display name), to see the exact time the email was sent, or to confirm that an attachment is present in the file. Most people never need to read an EML file this way, but it's good to know you can if something seems wrong with the email.

Frequently Asked Questions

Can I open an EML file without an email program?

Yes. Any text editor — Notepad, Word, Google Docs — will open an EML file and show you the contents. You'll see the raw email structure with headers and encoded attachments, which looks messy but is readable. For a cleaner view, use your web browser: some browsers can display EML files in a readable format.

Is an EML file the same as a .msg file?

No. EML is a universal format that works across almost all email programs. MSG is Outlook's own format and doesn't open as easily in other programs. If you need to move an email between different email programs, EML is the better choice.

Can an EML file contain a virus?

An EML file itself is just text, so it cannot execute code or install malware. However, an attachment inside an EML file could be dangerous. Don't open attachments from EML files unless you trust the source and were expecting the file.

What if an EML file won't open in my email program?

The file might be corrupted, or your email program might not support EML format (though most do). Try opening it in a different email program, or try a text editor to see if the file contents are readable. If the file is very old or came from an unusual email system, it may need conversion using an online tool.

Can I edit an EML file and save it?

You can edit the text in a text editor, but changes are risky — you might break the file structure and make it unreadable by email programs. If you need to change an email, import it into your email program, edit it there, and export it again as a fresh EML file.