How to Open an .eml File

The fastest way, on any device, with nothing to install: drop the file into this .eml viewer. It reads the message in your browser — sender, date, formatting, and attachments — and the file never leaves your device.

If you'd rather use software you already have, here's every route, by platform.

Windows

Windows Mail (built in). Double-clicking usually just works, since Windows associates .eml with Mail by default. If it doesn't, right-click the file → Open with → Mail.

Outlook. Right-click → Open with → Outlook. Outlook opens .eml files fine even though its own format is .msg. If Outlook is installed but not offered, choose Choose another app → More apps → Look for another app on this PC, then browse to OUTLOOK.EXE in your Office program folder.

Thunderbird. Free, and the most reliable option if you're dealing with a lot of these. Once installed, double-clicking an .eml opens it in its own window.

Notepad, for a quick look. Right-click → Open with → Notepad. You'll see the headers and any plain-text body. Formatting and attachments won't render, but it answers "who sent this and when" in about three seconds.

If Windows says it doesn't know how to open the file, nothing is associated with the extension. Either pick an app from that prompt, or use the browser viewer and skip the setup entirely.

macOS

Apple Mail handles .eml natively — double-click and it opens as a message. Mail may add it to your mailbox rather than opening it in isolation, which is worth knowing if you're keeping evidence separate from your working mail.

If double-clicking does nothing useful, right-click → Open With → Mail, or Get Info → Open with → choose an app → Change All.

Thunderbird works the same on macOS as on Windows and keeps the file out of your mailbox.

TextEdit shows the raw contents. Use File → Open rather than double-clicking, and you may need to choose "plain text" encoding.

iPhone and iPad

iOS has no .eml app, but it can preview them. If the file arrived as an attachment, tapping it usually shows a preview inside Mail. Files saved to the Files app can sometimes be previewed by long-pressing → Quick Look, though results vary by iOS version.

When that fails — which is common — open the file in Safari using a browser-based viewer. That works regardless of iOS version and doesn't require an app.

Android

Support depends heavily on the device and mail app. Gmail on Android generally won't open .eml attachments directly. Some file managers offer a text preview, which shows raw headers.

The dependable route is a browser viewer: open Chrome, choose the file, read the message.

Linux

Thunderbird, Evolution, and KMail all open .eml natively. From a terminal, less filename.eml shows the raw structure immediately.

Opening a lot of them at once

Mailbox exports and legal holds often produce hundreds or thousands of .eml files. A few things that help:

• Thunderbird with the ImportExportTools NG add-on can import an entire directory into a local folder, making the batch searchable.
• Search inside the files without opening them. On Windows, findstr /s /i "keyword" *.eml from a command prompt. On macOS or Linux, grep -ril "keyword" . — because the files are plain text, this works well.
• Watch the file names. Exports often name files by subject line, which can collide or truncate. Sort by size to spot the ones with large attachments.

Why the file might not open properly

It shows as a text file full of gibberish. You're looking at the raw source, and the section you're seeing is probably base64-encoded — an attachment or an encoded body. That's normal. You need a viewer, not a text editor.

It opens but the message is blank. The email likely has only an HTML body, and whatever you opened it with is showing the plain-text part, which doesn't exist. A proper viewer will render the HTML.

Images are missing. Most viewers block remote images by default. That's deliberate — they're frequently tracking pixels that report when a message is opened. There's usually a toggle to load them if you trust the sender.

The extension is wrong. Some systems save messages as .txt or with no extension at all. If a text file starts with lines like Received: and From:, it's an email — rename it to .eml.

It's actually an .msg file. These are Outlook's format and are not plain text. If the raw file looks like binary garbage from the very first character, that's what you have. Here's the difference.

Common questions

What is the default program for .eml files? On Windows, Mail or Outlook. On macOS, Apple Mail. If nothing is set, Windows will prompt you to choose.

Can I open an .eml file in Gmail? Not directly — Gmail's web interface has no import for individual files. You can forward the .eml to yourself as an attachment, but Gmail will show it as a file to download rather than rendering it. A browser viewer is faster.

Can I open an .eml without any email program? Yes. This viewer runs entirely in your browser with nothing installed and nothing uploaded.

How do I get the attachments out? Any real viewer lists them as downloadable files. A text editor won't — the attachment is base64-encoded inside the message and needs decoding.

How do I save it as a PDF? Open it, then print to PDF. Step by step here.

Open your .eml file now — free, no install, nothing uploaded.