EML is a file format developed by Microsoft for Outlook and Outlook Express. EML files are zipped emails that preserve the original HTML format and headers. Most email clients support EML files, but if you don't have an email client or are trying to open such files on a mobile device, there are workarounds that can be used to open the EML file.
Steps
Troubleshooting

Step 1. EML files won't open in Outlook Express
This is usually because the EML extension is associated with another program. In this case, please reset the file associations for Outlook Express.
- Close Outlook Express.
- Press ⊞ Win + R.
- Type msimn / reg and press ↵ Enter. This command will reset file associations for Outlook Express. EML files should now open automatically in Outlook Express (after double clicking on them).

Step 2. Check the extension
Some users have reported that Windows Live Mail backups change the *.eml extension to *._ eml. If the eml file does not open, check to see if its extension has changed.
- See step 2 in the next section for how to display file extensions (if you have them hidden).
- Change the extension *._ eml to *.eml by removing the _.
Method 1 of 4: Windows

Step 1. Open the file in your mail client
EML files are emails in the form of files. The easiest way to open EML files is to use an email client like Outlook, Outlook Express, Windows Live Mail, Thunderbird. Double click on the EML file to automatically open it in your email client.
- By opening the EML file in your email client, you can download email attachments and view text and graphics.
- If you don't have an email client, or you can't open files in your email client, read on.

Step 2. Change the file extension to open it in a browser
EML files are very similar to MHTML files, so change the file extension to *.mht to open it in Internet Explorer. MHT files can be opened in other browsers, but only Internet Explorer will display the content of such files correctly. This method will prevent you from downloading email attachments.
- If file extensions are hidden, show them. In Windows 8, check the box next to File Extensions in the View tab in any Explorer window. On older versions of Windows, open Control Panel and select Folder Options. Go to the "View" tab and uncheck "Hide extensions for registered file types."
- Right click on the EML file and select Rename.
- Replace the.eml extension with.mht. The system will warn you that replacing the extension may cause problems with the file. Confirm that you want to change the extension.
- Open the file in Internet Explorer. Typically, this browser opens MHT files by default. You can right-click on the file and select "Open With" - "Internet Explorer". Internet Explorer will open the MHT file in much the same way that an email client opens an EML file.

Step 3. Download and install FreeViewer EML File Viewer
It is available for free on the developer's site:
- Now find the folder with the EML files.
- Double click on this folder. EML files will be added to the program and you can open any of them.
- You can also view any email attachments.

Step 4. View the file as plain text
If you are unable to open the file in your email client and convert it to open in Internet Explorer, you can view the EML file as a regular text file. It will contain many incomprehensible symbols, but you can read the text of the letter and find links. You will not be able to view images or email attachments.
- Right click on the EML file and select Open With.
- Select Notepad from the list of programs.
- Find tags and. They indicate the beginning of the email body. You can find the text of the letter within these tags, and you can also scan the entire HTML code for any text.
- Find the <a href = tag pointing to links. You can copy and paste them into your web browser to follow the links from the EML file.
Method 2 of 4: Mac OS

Step 1. Open the EML file in Apple Mail
Apple Mail ships with Mac OS X and can open and display the content of EML files correctly.
- Right-click (or press Ctrl and left-click) the EML file and select Open With.
- Select "Mail" from the list of programs. The EML file will open in Apple Mail. You can do this even if you don't have an email account yet.

Step 2. Use Microsoft Entourage or Outlook (for Macintosh)
If you have Office 2008 or 2011, you can install Microsoft mail client to open EML files. Office 2008 includes Entourage, and Office 2011 replaces Entourage with Outlook (for Macintosh). You may not have installed the email client during the installation of the Office software.
When the installation is complete, right-click (or Ctrl-click and left-click) the EML file and select Open With. Select Entourage or Outlook from the list of programs

Step 3. Unpack the file using StuffIt Expander
It is a free archiver for OS X and can be used to extract information from an EML file.
- Download and install this archiver. You can do this at my.smithmicro.com/stuffit-expander-mac.html or in the Mac App Store.
- Drag the EML file into the StuffIt window. You can unpack multiple EML files at once by dragging and dropping them into the program window.
- Open the folders that are created for each EML file. In them you will find attachments to letters and images (in the form of separate files), as well as text files with the text of letters.

Step 4. View the EML file as plain text
If you do not have an email client and cannot install StuffIt Expander (for example, due to limited user rights), open the EML file in TextEdit. This will allow you to read the text of the letter and find any links. You will not be able to view images or download email attachments.
- Right-click (or press Ctrl and left-click) the EML file and select Open With.
- Select "TextEdit" from the list of programs.
- Find tags. They point to the body of the email. Find the <a href = tag pointing to links.
Method 3 of 4: iPad

Step 1. Download and install the Klammer app
This app is available in the App Store and costs only 99 cents. There you can open and view the contents of the EML file. This is currently the only way to view EML files on iPad (without having to convert them).

Step 2. Open the Mail application (or whichever application contains the EML file)
You can use Klammer to view EML files attached to emails, added to Dropbox or other cloud storage, or any other program that works with such files.
- If you're using the Mail app, click on the attachment to start downloading it to your iPad. If you're using Dropbox or Google Drive, download the file to iPad.
- If the attachment does not download, forward the email to yourself and try downloading the file again.

Step 3. Click on the downloaded file
You will be prompted to select the application in which this file will open.

Step 4. Click "Open in Klammer"
The EML file will be loaded into the Klammer app and you can view the contents of this file.
Method 4 of 4: Android

Step 1. Download the free EML Reader Free app
Android does not support EML format, so please use this app.
EML Reader FREE is popular, but not the only application to open EML files. If you want, install a similar application by finding it in the Google Play store (in the search box, enter "eml reader" (without quotes))

Step 2. Open the EML file
There are several ways to do this, depending on how you got the file.
- If you received an EML file as an attachment, open the email through the Gmail or Mail app and click on the EML file attachment.
- If you downloaded the EML file from the site, use the File Manager application to open the Download folder, or open the EML Reader FREE application to navigate the EML files.

Step 3. Select "EML Reader FREE" from the list of applications
When you try to open an EML file, you will be prompted to select an application. EML Reader FREE should appear in the list of applications. Click Always to associate EML files with this application.

Step 4. View the EML file
EML Reader FREE splits EML file into sections: "Address", "Date", "Subject", "Text", "HTML" and "Attachments".
- Section "Text" contains the text of the letter.
- The HTML section contains the letter in its original format.

Step 5. Press and hold the attachment to open it
At the bottom of the screen, you will see a list of attachments. These are all images that were used to create the HTML message, as well as any files that were not attached to the email.