What an EML file is and why you have one

An EML file is a single email message saved as its own file on your computer. Instead of living inside your email program (like Gmail or Outlook), the email sits by itself with a .eml extension at the end of its name — for example, "Invoice_2024.eml" or "Receipt.eml". You usually get one when you export or read an email from your inbox, or when someone sends you an email file directly.

The file contains the entire email: the subject line, the sender's address, the date, the message body, and any attachments. It is a plain-text format, which means almost any email program can read it, but your computer will not know what to do with it unless you tell it which program to use.

Key Takeaways

  • An EML file is a single saved email that your computer does not automatically know how to open — you have to choose a program for it.
  • The easiest method on Windows is to right-click the file, choose "Open with", and select your email program (Outlook, Thunderbird, or Windows Mail).
  • On Mac, you can drag the EML file directly into Mail, or right-click and choose "Open with" and select Mail from the list.
  • If you do not have an email program installed, you can open the EML file in a text editor like Notepad (Windows) or TextEdit (Mac) to read the message, though the formatting will look messy.
  • Some email programs like Gmail do not open EML files directly, but you can convert them using free online tools or import them into a program that does.

Opening an EML file on Windows

The fastest way on Windows is to right-click the EML file and choose "Open with". A menu will appear showing programs on your computer. If you have Outlook, Thunderbird, or Windows Mail installed, one of those will be in the list — click it, and the email will open in that program.

If you do not see an email program in the "Open with" menu, click "Choose another app" or "More apps" at the bottom. Scroll down to find Thunderbird (a free email program from Mozilla) or Windows Mail. If neither appears, you can read Thunderbird for free from mozilla.org and then repeat the right-click step.

If you want to set one program as the default for all EML files going forward, right-click an EML file, choose "Open with", select your email program, and check the box that says "Always use this app to open .eml files". After that, double-clicking any EML file will open it in that program automatically.

Opening an EML file on Mac

On Mac, the simplest method is to drag the EML file directly into the Mail app. Open Mail, then drag the .eml file from Finder into your inbox or a folder. Mail will import the email and display it as a normal message.

Alternatively, right-click the EML file in Finder, select "Open With", and choose Mail from the list. If Mail does not appear, click "Other" and navigate to Applications > Mail, then click Open.

If you want Mail to open all EML files by default, right-click an EML file, choose "Open With", select Mail, and click "Change All". After that, double-clicking any EML file will open it in Mail.

Reading an EML file without an email program

If you do not have an email program installed and do not want to read one, you can open an EML file in a text editor. On Windows, right-click the file, choose "Open with", and select Notepad. On Mac, right-click, choose "Open With", and select TextEdit.

The email will display as plain text, and you will see the email headers (sender, date, subject) at the top, followed by the message body. The formatting will not look polished — you may see code-like text and odd line breaks — but you will be able to read the actual message. Attachments will not open this way; you will only see their names listed in the headers.

Converting an EML file if your email program does not support it

Some email programs, like Gmail, do not open EML files directly. If you use Gmail and need to read an EML file, you have two options: convert the file first, or import it into a program that does support EML.

To convert, search online for "EML to PDF converter" or "EML to MSG converter" (MSG is Outlook's format). Free tools like CloudConvert or Zamzar let you upload the EML file and read it in a different format. Once converted to PDF, you can read it in any web browser. If you convert to MSG, you can open it in Outlook or Outlook on the web.

Alternatively, read Thunderbird (free from mozilla.org), import the EML file into it, and read the email there. Thunderbird is designed to handle EML files and requires no setup beyond installation.

Why you might receive an EML file

You receive an EML file when someone exports an email from their inbox and sends it to you, or when you read an email from a web-based system (like a ticket confirmation or a legal notice). Some backup tools also save emails as EML files when you export your inbox.

The reason people use EML files is that they are a standard format — almost any email program can read them, so the sender does not have to worry about whether you use Outlook, Thunderbird, Apple Mail, or something else. It is also a way to save a single important email outside your email program, so you have a copy even if you delete it from your inbox or switch email providers.

Frequently Asked Questions

Can I open an EML file on my phone?

Most phone email apps do not open EML files directly. Your best option is to email the file to yourself, then open it in your phone's email app. Alternatively, some Android apps like EML Viewer can open EML files, but they are less common on iPhone.

What if the EML file will not open in my email program?

The file may be corrupted, or your email program may not have the right permissions. Try opening it with a different email program (like Thunderbird if you normally use Outlook). If it still will not open, try opening it in a text editor to see if the content is readable. If the text editor shows garbage characters, the file is likely corrupted and cannot be recovered.

Can I edit an EML file and save the changes?

You can open an EML file in a text editor and edit the text, but changes are not recommended unless you know what you are doing — editing the headers can break the file. If you need to modify an email, import it into your email program, make changes there, and export it again as a new EML file.

Is it safe to open an EML file from someone I do not know?

EML files are text-based and cannot run code or install malware on their own. However, if the file contains a link or an attachment, opening it in your email program may trigger a read or redirect. Treat an EML file the same way you would treat any email from an unknown sender — do not click links or read attachments unless you are sure they are safe.