When sending and receiving emails, some technical nuances are involved, like file formats. The most popular formats are MSG and EML. Most email clients use either one of these formats, but to know which one works best for your business or personal use, you must understand the difference between them. 

    Explained: Msg and Eml Formats

    The MSG file format is specific to Microsoft Outlook. Although it includes the same data as an EML file, there is additional information like the recipient’s name, the sender’s name, and the message subject. The file format is used to store individual mailbox items, which might be contacts, messages, journal entries, calendar events, notes, and tasks. 

    A single MSG file contains one Outlook item, along with its properties. The .msg format is considered reliable and convenient when transferring and saving scattered information from several Outlook mailboxes. 

    The EML format, on the other hand, is commonly used for transferring and saving email messages across email systems. This format is used by various email clients, including Apple Mail, Outlook, Thunderbird, etc. It is also possible for other email clients to open or import EML files without requiring additional tools. 

    The EML file is a plain text file containing attachments, the body, and header information. Most email apps can easily open these files for viewing. Users can use a text editor to use EML files. 

    One .eml file contains one message with all the contents, including attachments, images, and formatting. 

    How to Open Msg Files?

    • On Mac

    The Outlook application on your Mac is not an MSG viewer. So, how to read msg files on Mac? You have to use Outlook’s web version as an MSG file viewer. Log into your Outlook account and email the .msg file Mac to that address as an attachment. When you receive the email, open it and download the attachment. 

    • On Windows 

    You can open MSG files on Windows using the Outlook desktop application. Is Outlook installed and set up? Then, the format will be associated with Outlook. You can open an MSG file by double-clicking on the file. If Outlook is not associated, right-click on the file and select Open With > Outlook. 

    How to Open Eml Files?

    • On Mac

    Locate the EML file and open it using the Mail app on your Mac. Right-click on the file > Open With > Mail. 

    • On Windows 

    You can open EML files by right-clicking on the file and opening it with Windows Mail. You can also open it via Microsoft Outlook. 

    Difference Between Eml and Msg Files 

    Metrics EML files MSG files
    Purpose Designed to store individual emailsDesigned to view, store, import and export individual Outlook mailbox items
    Versatility Can be opened in different email applications Only supported by Microsoft Outlook 
    Cross-platform Universal files and can be opened across operating systems and devices Designed for Outlook and can be opened in Windows. Mac users have to use some workarounds to open these files. 
    File contents Contains most of the message data, including attachmentsContains all internal properties and fields of messages and other mailbox items 
    File size These files are bulky Individual files do not take up much space, but if this is your primary format of storing emails, the total size may become significant. 

    Advantages of the Msg File Format 

    MSG files offer some advantages compared to EML files. These files are larger, storing more data in each file. This format makes it convenient for businesses to send or store emails with large attachments. Also, the files contain additional information, such as the message subject, sender’s name, etc. Such information makes it easier to find emails. 

    The format also supports voting buttons, custom fields, and more in Outlook. 

    Advantages of The Eml File Format 

    EML files offer a compatibility advantage because this format can be used across devices and operating systems. These files can be easily opened without requiring additional tools. 

    Which Is The Best Format?

    It is difficult to answer which format is the best. MSG files can only be opened in Outlook, while EML files are compatible with most email clients and operating systems. But the EML files are bulky, which may pose a problem when storing and transferring these files. MSG files, on the other hand, do not take up much space unless you are storing too many of them. 

    The choice between MSG and EML ultimately boils down to your preferences and requirements. If you only use Outlook, MSG is a better option. But if you use multiple email clients, EML might be a better choice. 

    Vet your options carefully and then make an informed decision. 


    Now you have important information about EML and MSG formats. Weigh the pros and cons of both file formats and decide which one is the best for your business or personal use.