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

An EML file is a text file that contains one complete email — the message itself, the sender's address, the recipient's address, the subject line, and any attachments. The letters stand for "Electronic Mail". When you export an email from Outlook, Thunderbird, Apple Mail, or most other email programs, you get an EML file. You can also receive one as an attachment when someone forwards you their email in this format.

EML files are useful because they preserve the entire email exactly as it was, including headers and formatting, without tying you to any particular email program. If you need to save an important email permanently, move emails between different email clients, or share an email with someone else, an EML file is a straightforward way to do it.

Key Takeaways

  • An EML file is a single exported email stored as plain text that any email program can read.
  • You create an EML file by exporting or saving an email from your email client, not by downloading it from the internet.
  • Opening an EML file usually means double-clicking it, which will open it in your default email program, or right-clicking to choose a different program.
  • If you cannot open an EML file, you can rename it to .txt and read the raw email content in any text editor like Notepad.

How EML files are created

You do not download EML files — you create them yourself by exporting emails from your email program. In Outlook, you right-click an email and select "Save As", then choose a location on your computer and the file saves as .eml. In Thunderbird, you right-click the email and select "Save As". In Apple Mail, you drag the email to your desktop or a folder, and it becomes an EML file automatically.

Some email programs also let you export entire folders of emails at once, which creates multiple EML files in a single operation. This is common when you are switching email clients and want to move your entire inbox to a new program.

Opening an EML file on Windows

The simplest way is to double-click the EML file. Windows will open it in your default email program — usually Outlook if you have it installed, or Windows Mail if you do not. The email displays exactly as it was when it was exported, with all headers, formatting, and any embedded images intact.

If double-clicking does not work, or you want to open it in a different program, right-click the EML file and select "Open with". You will see a list of programs on your computer that can read EML files. Choose Thunderbird, Gmail (if you have the desktop app), or any other email client you have installed. If you do not see any email programs in the list, you can browse your computer to find one manually.

If you want to read the raw email content — the headers, the plain text, everything — without using an email program, right-click the EML file, select "Open with", and choose Notepad. The file will open as text, and you will see the email's internal structure, including sender information, routing details, and the message body.

Opening an EML file on Mac

Double-click the EML file and it will open in Apple Mail by default. The email displays with all its original formatting and attachments. If you want to open it in a different program, right-click (or Control-click) the EML file, select "Open With", and choose Thunderbird, Gmail, or another email client from the list.

To read the file as plain text, right-click the EML file, select "Open With", and choose TextEdit. The file will display as raw text showing all the email headers and content. You can also drag an EML file directly into Mail and it will import the email into your inbox.

What to do if you cannot open an EML file

If double-clicking the EML file does nothing, your computer does not have a default email program set. Right-click the file, select "Open with", and manually choose an email program from the list. If you do not see any email programs, you may need to install one — Thunderbird is free and works on Windows and Mac.

If the file is corrupted or incomplete, you may see an error message when you try to open it. Try opening it as plain text in Notepad (Windows) or TextEdit (Mac) to see if the content is readable. If the file is very small — just a few kilobytes — it may be incomplete and the person who sent it to you may need to export it again.

If you received an EML file as an attachment in an email and cannot open it, check that the file actually downloaded completely. Some email programs block certain file types, so the attachment may have been stripped out. Ask the sender to try again or to send the email in a different format.

EML files versus other email formats

EML is the most common format for exporting single emails because it is simple and widely supported. MSG files are similar but are specific to Outlook and contain more metadata. MBOX files store multiple emails in one file and are used by Thunderbird and some other programs. PST files are Outlook's native format for storing entire mailboxes.

If you need to move emails between programs, EML is usually the safest choice because nearly every email client can read it. If you are archiving emails long-term, EML is also a good choice because the format is unlikely to become obsolete — it is just plain text with a standard structure.

Frequently Asked Questions

Can I open an EML file without an email program?

Yes. Right-click the EML file, select "Open with", and choose Notepad (Windows) or TextEdit (Mac). You will see the email as plain text, including all headers and the message body. It will not be as readable as opening it in an email program, but you can read the content.

What happens if I delete an EML file?

The file is deleted from your computer, but the original email remains in your email account unless you deleted that too. EML files are just copies of emails you have exported. Deleting the EML file does not affect your email account.

Can I edit an EML file?

Technically yes — you can open it in a text editor and change the text. However, most email programs will not recognize the edited file as a valid email, and you may not be able to open it afterward. It is safer to treat EML files as read-only archives.

Why would someone send me an EML file instead of just forwarding the email?

They may be forwarding an email from an account they no longer have access to, or they want to preserve the exact original formatting and headers without any changes. Forwarding adds new headers and can alter the appearance, while an EML file keeps everything exactly as it was.

Is an EML file the same as a .eml attachment?

Yes. The .eml is the file extension that identifies it as an email file. When you see a file named "message.eml", the .eml part tells your computer it is an email file and which programs can open it.