What an EML file is and why you have one

An EML file is a single email message saved as a text file. It contains the email's subject line, sender, recipient, date, and body text — everything you see when you read an email in your inbox. Email programs like Outlook, Thunderbird, and Apple Mail create EML files when you export or save individual messages.

You might have an EML file because someone sent it to you, you exported it from an email program yourself, or a backup tool created it. Unlike a regular email sitting in your inbox, an EML file is just a file on your computer — it doesn't need an email account to open.

The file extension is always .eml at the end of the filename. If you see something like message.eml or invoice.eml, that's an EML file.

Key Takeaways

  • EML files open in any email program, including Outlook, Thunderbird, Apple Mail, and Gmail through your web browser.
  • On Windows, right-click the EML file, select "Open with", and choose your email program from the list.
  • On Mac, double-click the EML file and it will usually open in your default email program automatically.
  • If no email program is installed, you can open an EML file in a text editor like Notepad or TextEdit to read the raw content, though formatting may look messy.
  • Some online tools let you upload an EML file and view it in your web browser without installing anything.

Opening an EML file on Windows

The easiest way is to use an email program you already have. If you use Outlook, Thunderbird, or another email client, right-click the EML file and select Open with. A menu will appear showing installed programs. Click the email program you want to use, and the message will open inside it.

If no email program appears in the "Open with" menu, you can browse for one manually. Select Open with again, then click Choose another app at the bottom. Scroll down and look for Outlook, Thunderbird, or Windows Mail. If you see one, click it and check the box that says "Always use this app to open .eml files" so future EML files open the same way automatically.

If you don't have an email program installed, you can still read the file. Right-click it, select Open with, and choose Notepad or any text editor. The email will display as plain text with headers (sender, date, subject) at the top and the message body below. Attachments will show as code rather than as downloadable files.

Opening an EML file on Mac

On Mac, double-click the EML file. If you have Apple Mail installed (which comes with macOS), the file will open automatically in Mail and display the full email with formatting intact.

If the file doesn't open, or if you want to use a different email program, right-click the EML file and select Open With. A submenu will show available programs. Choose your email client — Outlook, Thunderbird, or another program — and the message will open there.

If you don't have an email program, open the file with TextEdit instead. Right-click the EML file, select Open With, and choose TextEdit. The email will display as text, though it may be harder to read than in an email program.

Opening an EML file on Linux

Most Linux systems have Thunderbird or Evolution installed by default. To open an EML file, right-click it and select Open With. Choose Thunderbird or Evolution from the menu, and the email will open inside the program.

If you prefer a text editor, you can also right-click and select Open With, then choose a text editor like gedit, Kate, or nano. The email will display as plain text with all headers visible.

Using Gmail or web-based email to open an EML file

If you don't want to install an email program, you can upload an EML file to Gmail and read it there. Open Gmail in your web browser, click the gear icon in the top right, and select Settings. Go to the Forwarding and POP/IMAP tab and enable IMAP if it isn't already on. Then use a tool like EML Viewer Online or Encryptomatic's EML Viewer — both are free and require only that you upload the file. The email will display in your browser without saving anything to your computer.

These online tools are useful if you receive an EML file occasionally and don't want to set up an email program. They work on any device with a web browser.

What to do if the EML file won't open

If double-clicking or right-clicking doesn't work, the file may be corrupted or the filename may be wrong. Check that the file actually ends in .eml — if it ends in something else like .eml.txt, rename it to remove the extra extension and try again.

If the file is genuinely corrupted, an email program may refuse to open it. In that case, try opening it in a text editor to see if you can read the content as plain text. You'll see the email headers and body, though attachments won't be usable.

If you're certain the file is an EML file but nothing opens it, try installing Thunderbird (free, available for Windows, Mac, and Linux). Thunderbird opens almost any EML file, even damaged ones, and is designed specifically for email.

Understanding what you see when you open an EML file

When an EML file opens in an email program, it looks like a normal email — you see the sender, recipient, subject, date, and message body. If the email had attachments when it was saved, they appear as downloadable files in the message.

If you open an EML file in a text editor, you'll see the raw content. At the top are headers like From:, To:, Subject:, and Date:. Below that is the message body. If there are attachments, they appear as long strings of encoded text (usually starting with Content-Transfer-Encoding: base64). This is normal — the text editor is showing you the file's actual structure, not how it's meant to be displayed.

Frequently Asked Questions

Can I convert an EML file to PDF?

Yes. Open the EML file in your email program, then use the program's print function (Ctrl+P on Windows, Cmd+P on Mac). Select "Print to PDF" or "Save as PDF" instead of printing to a physical printer. The email will be saved as a PDF file you can share or store.

What if I have hundreds of EML files to open?

If you have many EML files, import them into an email program rather than opening them one at a time. Thunderbird and Outlook both have import functions that can read entire folders of EML files at once. Check your email program's help menu for "import" or "import messages".

Is it safe to open an EML file from someone I don't know?

EML files are text files and cannot run code or install software on their own. However, if the email contains a link or attachment, opening it in an email program will display those just as a regular email would. Use the same judgment you would with any email — don't click suspicious links or download unexpected attachments.

Can I edit an EML file and save the changes?

You can edit an EML file in a text editor, but changes are difficult to make correctly because of the file's structure. If you need to edit an email, open it in your email program, copy the text you want, and paste it into a new message instead. That's simpler and safer than editing the raw file.

Why is my EML file so large?

EML files are large when they contain attachments. The attachments are encoded as text inside the file, which makes them take up more space than they would in a folder. If you need to save space, extract the attachments from the email (most email programs let you right-click an attachment and select "Save") and delete the EML file.