How to Open MSG File Without Outlook (Windows, Mac, Online)

Someone forwards you a file ending in .msg, you double-click it, and Windows shrugs. Or it opens as a screen of binary garbage. Or your Mac offers to open it in TextEdit, which helps nobody. A .msg file is a single email that Outlook saved to disk, and it behaves differently from the .eml files every other mail program produces. That difference is the whole reason it will not open. Below is how to open one on Windows, on a Mac, and in a browser, with and without Outlook installed, plus the trick that does not work no matter how many blog posts recommend it.

How do I open a MSG file?

Double-click the .msg file. If Microsoft Outlook is installed, it opens the message straight away, with the sender, subject, body, and attachments intact. If Outlook is not installed, Windows will not know what to do with it, and you need either a standalone MSG viewer, an online viewer, or a converter that turns the file into a format your mail app understands.

That is the short version, and for most people with a work laptop it is the end of the story. The complications start on machines without Outlook, which is where the rest of this guide lives.

What is a MSG file?

A MSG file is a single Outlook email, appointment, contact, or task saved as its own file. It stores the sender, all recipients, the date, subject, plain-text and HTML bodies, attachments, and a large set of Outlook-specific properties. Microsoft writes it in a binary container rather than plain text, which is why a text editor shows gibberish.

The container is called Compound File Binary Format, and inside it Outlook stores each piece of the message as a separate stream tagged with a MAPI property code. It is essentially a tiny filesystem inside one file. Compare that with an EML file, which is plain text you can read in Notepad, and you can see why one opens everywhere and the other does not.

How do I open a MSG file without Outlook?

You have three practical routes without Outlook: install a free standalone MSG viewer, upload the file to an online MSG viewer in your browser, or convert the .msg to .eml with a converter and open the result in Windows Mail, Thunderbird, or Apple Mail. The browser route is fastest for a one-off file; a viewer app is better if you handle MSG files regularly.

One caution on online viewers. You are uploading a business email, headers and all, to a third party you may know nothing about. For a message about lunch, fine. For a contract, a payroll thread, or anything covered by a client confidentiality agreement, use a local viewer or convert the file on a machine you control.

The last row is a different job from the first four. A viewer shows you one message. A parser turns a folder of messages into rows.

Can I open a MSG file on a Mac?

Outlook for Mac opens .msg files directly. Apple Mail does not: it has no native support for the format and will either refuse the file or import it as an attachment you cannot read. Without Outlook for Mac, convert the .msg to .eml first, then double-click the result, and Apple Mail opens it like any other saved message.

Do not bother with TextEdit. Because the file is a binary compound document, TextEdit shows you fragments of readable text swimming in control characters. You might spot the subject line. You will not get a usable message.

Can I open a MSG file in Gmail?

No. Gmail cannot open or import .msg files, and attaching one to a message just passes the unreadable file along to the next person. If a .msg arrives in Gmail as an attachment, download it and open it with one of the methods above, or convert it to .eml, which Gmail also will not open directly but which any desktop mail client will.

Can Notepad open a MSG file?

Notepad will open it and show mostly nonsense. You will see stretches of readable characters, often with a space between every letter, because Outlook stores strings as UTF-16, and Notepad renders the extra zero bytes as junk. The subject and a few addresses may be legible. The formatting, the attachments, and the structure are not recoverable this way.

This is the honest answer to a question a lot of people ask after trying it. It is also the reason the rename trick fails.

Does renaming a MSG file to EML work?

No. Renaming .msg to .eml changes the extension, not the contents. EML is plain-text MIME and MSG is a binary compound file, so a mail client that trusts the new extension will try to read the binary as text and fail. You need an actual converter that reads the MSG structure and writes valid MIME, not a rename.

This one circulates widely because it sometimes appears to half work: the client opens the file, shows a subject, and drops everything else. That is not a converted email, it is a corrupted one, and if you are handling records that matter, a message that silently loses its recipients and attachments is worse than one that refuses to open.

Why won't my MSG file open?

The three common causes are no Outlook installed, a file association pointing at the wrong program, or a truncated download. Right-click the file, choose Open with, and pick a mail app or viewer. If it still fails, check the file size: a .msg under a couple of kilobytes usually means the download or the export did not finish.

A fourth cause catches people out in mixed environments. Some archiving and ticketing systems export files with a .msg extension that are not really MSG at all, but plain MIME with the wrong name. If a viewer rejects the file, try opening it in a text editor. If you can read the headers as normal text, it is an EML wearing the wrong extension, and renaming it to .eml genuinely does work in that one case.

What is the difference between a MSG file and an EML file?

MSG is Microsoft's binary format, written by Outlook, and it carries Outlook-specific properties alongside the message. EML is the plain-text standard used by nearly everything else, including Thunderbird, Apple Mail, and Gmail exports. EML opens almost anywhere; MSG expects Outlook. Both hold one email each.

The practical consequence is portability. If you are choosing a format to archive messages in, EML travels better. Our fuller breakdown of EML vs MSG files covers when each format shows up and which one to keep, and if you are dealing with the other format today, the guide on how to open an EML file walks through the same ground for .eml.

How do I get the data out of MSG files into Excel?

Opening a message and reading it is one problem. Getting the sender, date, subject, and the values buried in the body of two hundred messages into a spreadsheet is a different one, and no viewer solves it. For that you need a parser that reads each .msg, pulls the fields you name, and writes one row per email.

MailParse reads .msg and .eml files directly in the browser, without Outlook installed, and exports the sender, recipients, date, subject, body, and attachment filenames to Excel, CSV, or JSON. You can name custom fields too, such as an invoice number or a purchase order reference sitting in the body text, and each becomes its own column. Drop in one file or a folder of thousands. The walkthrough on how to convert MSG files to Excel covers the batch case step by step, and the MSG to Excel converter does it now.

One limit worth naming: a parser reads the email. If the number you actually need is printed inside an attached PDF invoice, that is a document extraction job rather than an email one, and the right move is to pull the totals out of the PDF invoice into a spreadsheet separately, then join the two on the invoice number.

Is it safe to open a MSG file?

Opening a .msg to read it is about as safe as reading any email, with the same caveats: do not open attachments you did not expect, and do not click links from senders you cannot verify. The file format itself is not the risk. The attachments and links it carries are, exactly as they would be in your inbox.

The one format-specific concern is that a .msg can carry an embedded attachment that a viewer offers to open for you. Treat that the same way you would treat the attachment arriving by mail, because it is the same file.

Where to start

If you have Outlook, double-click and move on. If you do not, a local viewer keeps your mail on your machine and an online viewer is quicker for a single harmless message. Convert to .eml when you want the message to live in Thunderbird or Apple Mail long term. And when the goal was never really to read the email but to get what is inside it into a spreadsheet, skip the viewers entirely and parse the files instead.