Read time 7 minutes

Summary: EML files, developed by Microsoft, are commonly used for emails. They can be accessed using various email clients. To open EML files in MS Outlook, change the default application settings or use ad hoc techniques, but it’s recommended to use a dependable EML Viewer tool for a seamless process.

EML stands for ‘Email Message’ and has been developed by Microsoft Corporation. Out of the box, EML files can be accessed using Outlook Express, which came preinstalled with the Windows XP operating system. The EML file format adheres to a standardized structure, typically comprising a header and the message body. Thanks to its adherence to email standards, EML files are compatible with a wide range of third-party applications, servers, and email clients.

By default, when you have Outlook 2010 or a later version installed on your computer, EML files will automatically open in Outlook. If you encounter any issues opening them, you can set Outlook as the default program to ensure EML files open with it.

Nevertheless, if you’re utilizing Outlook 2003 or 2007, you’ll need to modify the registry configurations in order to open EML files within Outlook.

Changing the Default Application for EML Files to Outlook

Setting Outlook as the default application for EML files is a straightforward process, even if you’re unsure of its location within the Windows system.

  1. Go to the Default App dialog box with the following steps:
    • Windows 7
      Start >> Default Program >> Associate a file type or protocol with a program
    • Windows 8 and Windows 8.1
      Start >> type: Default Programs >> Associate a file type or protocol with a program
    • Windows 10
      Start >> Settings >> Apps >> Default Apps >> Choose Default apps by file type
  2. The file extension list will appear on the screen, find the .eml file extension here.
  3. Click on the application icon behind it or click the ‘Change program’ button at the top in Control Panel.
  4. A pop-up window will appear on the screen, select Outlook from it.

Doing so will set MS Outlook as the default application for EML files.

Instant Solution

Kernel for EML to PST Converter an automated tool to migrate Windows Live Mail files to Outlook PST file format without any error.

Reasons to Open EML files in MS Outlook

Over the years, numerous individuals have utilized a variety of email clients, including Outlook Express and Windows Live Mail, which have since become outdated. Consequently, many users are now making the transition from these outdated email clients to MS Outlook, attracted by its array of advanced features. It’s worth noting that the EML format is associated with email clients designed for Windows platforms. Occasionally, with each new operating system release, Microsoft alters the default email client. For instance, in earlier Windows OS versions like XP, Outlook Express served as the default email client, while in subsequent Windows editions such as Vista and 7, it was replaced by Windows Mail and Windows Live Mail. These three email clients support different file formats, necessitating the need to open EML files in MS Outlook.

Ad hoc Techniques to Open EML Files in Outlook
  1. Making Outlook your default program to open EML files
    Go to the drive containing the EML files. Right-click and select ‘Open with’ and then select ‘Outlook.’ See the snippet below for more clarity.
    Open with’ and then select ‘Outlook.’
  2. Using Windows Live Mail (WLM) and MS Outlook
    Before moving any further, it is advisable to back up your data. Please follow the steps outlined below:

    1. Launch MS Outlook and WLM.
    2. In WLM, click File>Export email> Email messages
      Export email
    3. Now choose Microsoft Exchange as the export option and hit next. You will see a dialog box pop up (see below). Click Ok to proceed.
      choose Microsoft Exchange
    4. Next, you can either migrate all folders at once or some folders only. Choose the appropriate option.
      migrate all folders
    5. You will be prompted with a message of successful completion — hit Finish.
      NB: You might encounter an error at this stage of an unsuccessful export. This can be solved by making the Outlook as a default program for opening mails.
    6. Now open MS Outlook and look for the emails.
  3. Drag & drop EML files directly to MS Outlook
    This is by far the easiest method to export EML files to Outlook. If you have access to the EML files, you can drag and drop the EML files to Outlook.
  4. Open EML Files without Outlook
    These ad hoc methods may appear simple at first glance, but there’s no assurance that all your EML files will be seamlessly transferred to Outlook. If you’re dealing with a substantial volume of EML data, it will demand considerable time and effort on your part. Furthermore, there’s a risk that the manual process could inadvertently modify the SMTP header section of the EML file. For these reasons, it is strongly recommended to utilize a dependable EML Viewer tool. In our view, Kernel EML Viewer is a solution that can address all your EML access-related challenges. It stands out as a standalone tool, granting you the freedom to view EML files without the need for Outlook export. This tool offers automated EML file searching and includes a built-in feature for recursive subfolder exploration. Operating it is a breeze, following three simple steps: select, view, and save. Moreover, it provides an option to save email descriptions as HTML files. While the freeware version offers basic functionality, the personal and corporate license versions come with additional features such as:

    1. Converts EML/EMLX files to PST and MSG
    2. Filters EML/EMLX files before saving
    3. Supports multiple EML/EMLX file migration
    4. Migrates EML/EMLX files to Office 365

The snippet below shows the User Interface of the tool.


In this tutorial, we’ve explored methods for viewing and migrating EML files to Outlook versions 2019, 2016, and 2010. It’s clear that while ad hoc techniques can open EML files in Outlook, they are not advisable due to their unreliability, tedious nature, and time-consuming process. We recommend utilizing a third-party solution like “Kernel EML Viewer” for EML file viewing. This standalone tool eliminates the need for migrating EML files to Outlook and offers the advantage of data portability, enabling you to access your data from anywhere using the EML viewer tool.

Kernel for EML to PST