What is and how to open an EML file

  • EML files are a standard format for email messages, developed by Microsoft.
  • They contain a header with information about the sender and a body with the message and attached files.
  • They can be opened with email clients such as Microsoft Outlook and Mozilla Thunderbird.
  • They can also be opened with web browsers and text editors, although the display may vary.
Daniel Terrasa

5 minutes

eml file

We are all email users, and therefore we have all dealt with EML files on occasion. The extension (.eml) is actually an acronym for E-Mail. In this article we explain what it is and how to open an EML file.

This file type was developed by microsoft several decades ago to be able to comply with the industry standard RFC 5322, focused on the transfer of messages between email clients. It is a standard that makes use of the Internet Message Format (IMF) syntax, which is used in the text contained in E-mail messages.

Although there are many types of email message files (for example, DAT, EMLX, MBOX, or MSG, among others), the fact is that EML has managed to prevail over all of them. It is the most common and widely accepted format, especially due to the adoption of major email clients. By using it, the original HTML formatting and headers of the E-Mail can be maintained.

Thus, mail applications like Microsoft Outlook or Apple Mail, use the EML file for the message content and date, subject, sender, and recipient(s). In the same way, they can also store email attachments.

The structure of an EML file is always the same. It consists of two parts:

  • El header, which contains the sender's and recipient's addresses, the date and time, the subject, and other information.
  • El body, where the email message (including hyperlinks) and, if applicable, any attachments are located.

How to open an EML file

To open an EML file on a Windows computer, the easiest thing to do is to use an email client, although we can also do it through a web browser or even through a plain text editor program. We analyze the three methods:

With an email client

outlook mail

This is the most common and simple way to open an EML file. To clarify the term, mail clients are nothing more than the local applications that we have installed on our computer to manage this content. These are the two most common:

  • Microsoft Outlook, obviously. It is Microsoft software that allows the Office package. To open an EML file with Outlook, just right-click on it, choose the “Open with” option, and select Outlook.*
  • Mozilla Thunderbird, the open source email client developed by the Mozilla Foundation and accessible to anyone for free. It is perfectly compatible with EML files, so it can be used without problem to open them.

(*) To make this application always open files with this extension, check the box "Always use this application to open .eml files."

With a web browser

open eml with chrome

EML files are also supported by major browsers. This means that we can also use them to open them and see the text they contain. These are some of the most recommended:

  • Microsoft Edge. For obvious reasons, files of this type are fully supported. Simply drag and drop the file onto a blank tab to automatically display all of its content (read-only, no editing possible).
  • Google Chrome. For this purpose, it works exactly the same as Edge.

With a plain text editor

eml notepad

The advantage of using these applications, often so despised, is that In addition to reading the content of the EML file, we will also be able to edit it. Something that is not possible using the browser. The downside: the content is unstructured and somewhat confusing to look at. Even so, there are two good options:

  • Memo pad. Being a program from the Microsoft family, compatibility is absolute. When opening Notepad, first click on “File” and then “Open”. Then we start searching for “All files (*.*)” and select the EML file we want to see.
  • NotePad++. The great alternative to Notepad, a free software that is also compatible with this type of file.

Through applications

Finally, we will mention the possibility of opening EML files with applications specifically designed for this purpose. There are many of this type, so we will refer only to the two that enjoy the best opinion among users.

  • EML Reader, a free application, without purchases or ads, available in the Microsoft store. It is used to open files in the .eml format, faithfully preserving their original design. Just hover your mouse over the file, right-click and select the “Open EML File” option. That easy. Download link: EML Reader.
  • EML Viewer. Another free app (although there is a paid version with additional functions), very practical and intuitive. Download link: EML Viewer.