How to open a .msg file
Outlook message file · Email
A .msg file is a single email saved by Microsoft Outlook in its own proprietary format. With Outlook installed it opens on a double-click. Without it, you need a viewer, because unlike .eml it is not readable text.
What a .msg file actually is
MSG is Microsoft's single-message format, built on the Compound File Binary structure, the same container Office used for old .doc and .xls files. It stores the message, its properties and any attachments as separate internal streams.
This is the crucial difference from .eml. An EML is plain MIME text you can read in Notepad. An MSG is a binary container, so opening it in a text editor shows mostly garbage with a few readable fragments.
Why it will not open
Nothing outside the Microsoft ecosystem reads MSG natively. No text editor, no browser and no macOS application will show it properly, and Apple Mail cannot import it.
Step by step
Windows
- 01With Outlook installed, double-click the file. It opens as a normal message.
- 02Without Outlook, install a free MSG viewer, or upload nothing anywhere: many online converters keep a copy of your email on their servers.
- 03A safer offline route: rename a copy of the file to .zip and open it with 7-Zip. The compound structure often lets you pull out the attachments even if the message body stays unreadable.
- 04Best long-term fix: ask the sender to forward the message normally, or to save it as .eml instead, which everything can read.
macOS
- 01macOS has no native MSG support at all.
- 02Install a dedicated MSG viewer, or open the file on a Windows machine and re-save it as .eml.
- 03If you only need the attachments, try renaming a copy to .zip and opening it with Keka.
What usually goes wrong
Do not upload confidential email to online converters
MSG files usually turn up in legal, HR and finance contexts, which is precisely the content you should not paste into a free web converter. Whatever you upload sits on someone else's server.
MSG and EML are not interchangeable
EML is the open standard almost every client reads. MSG is Outlook-only. If you get to choose, always ask for EML.
Programs that open .msg
Our pick, in order. Every one links to the publisher's official download URL and the SHA-256 hash of the installer, so you can check the file before you run it.
Common questions
- How do I open a .msg file without Outlook?
- You need a dedicated MSG viewer, because the format is a proprietary binary container rather than text. To recover just the attachments offline, rename a copy to .zip and open it with 7-Zip. The cleanest fix is asking the sender to resend as .eml.
- What is the difference between .msg and .eml?
- EML is the open RFC 5322 format, plain MIME text that nearly every mail client reads. MSG is Microsoft's proprietary binary format for one saved Outlook message and needs Outlook or a specific viewer.
- Can I open a .msg file on a Mac?
- Not natively. Apple Mail cannot import MSG. You need a third-party viewer, or you convert the file to .eml on a Windows machine first.