Guide
How to Open an MSG File Without Outlook (5 Methods)
Published April 5, 2026 · 5 min read
Someone sends you an email attachment ending in .msg and your computer has no idea what to do with it. You’re not alone. MSG is Microsoft Outlook’s proprietary format for saving individual emails, and without Outlook installed, most operating systems won’t even preview it.
The good news: you don’t need a $150 Outlook license to read a .MSG file. Below are five practical methods that work on Windows, Mac, and Linux — ranging from quick online tools to full-featured desktop apps.
1. Use a free online MSG file viewer
The fastest option for a one-off file. Sites like Encryptomatic and Zamzar let you upload a .MSG file and view its contents in the browser. You’ll see the sender, recipients, subject, date, and body text — usually within seconds.
Pros: No install, works on any device.
Cons: Most viewers are read-only — you can’t export to PDF or save attachments separately. Some have file-size limits around 10 MB.
2. Open the MSG file in Mozilla Thunderbird
Thunderbird is a free, open-source email client that runs on Windows, Mac, and Linux. While it doesn’t natively open .MSG files, the ImportExportTools NG add-on adds that capability. Install the extension, then use Tools → ImportExportTools NG → Import MSG files to load your messages.
Pros: Free, handles attachments, works offline.
Cons: Requires installing Thunderbird plus an add-on. Not ideal if you just need to read one file quickly.
3. Convert MSG to EML and open with any email client
EML is the universal email format that Apple Mail, Thunderbird, and most other clients understand. Tools like MSGConvert (a Perl script available on Linux and Mac via Homebrew) can convert .MSG to .EML on the command line:
msgconvert message.msgThis creates message.eml, which you can double-click to open in your default mail app. This is a popular approach among IT teams managing Outlook MSG archives on non-Windows servers.
Pros: Scriptable, great for batch processing.
Cons: Command-line only. Requires Perl and the Email::Outlook::Message module.
4. Use a desktop MSG viewer (Windows or Mac)
If you regularly deal with .MSG files, a dedicated desktop viewer may be worth installing. On Windows, SysTools MSG Viewer and FreeViewer MSG Reader are popular free options. Mac users can try Klammer ($4.99 on the App Store), a lightweight Outlook MSG converter for macOS that previews messages and exports them as PDF or EML.
Pros: Works offline, handles large files.
Cons: Yet another app to install. Free versions may have limited export options.
5. Convert MSG to PDF online with MSG to PDF
If you need a clean, shareable document — not just a preview — MSG to PDF converts your .MSG files to properly formatted PDFs in seconds. It runs entirely in the browser, preserves email headers (From, To, Subject, Date), embeds inline images, and can export attachments alongside the PDF.
Unlike most Outlook MSG converters, MSG to PDF works on any operating system — including Mac, where Outlook alternatives are limited. There are no watermarks on any plan, and the free tier gives you 8 conversions per month without even creating an account.
Pros: No install, PDF output with headers and attachments, works on Mac/Windows/Linux, free tier available.
Cons: Requires an internet connection. Free tier limited to 8 conversions/month (Pro is unlimited at $9/mo).
Comparison table
| Method | Cost | Platform | PDF export | Install? |
|---|---|---|---|---|
| Online MSG viewer | Free | Any | No | No |
| Thunderbird + add-on | Free | Win / Mac / Linux | Limited | Yes |
| MSGConvert (CLI) | Free | Mac / Linux | No (EML only) | Yes |
| Desktop viewer | Free–$5 | Win or Mac | Some | Yes |
| MSG to PDF | Free / $9 mo | Any | Yes | No |
Which method should you use?
If you just need to peek at a single email, a free online viewer does the job. If you deal with .MSG files regularly on Mac or Linux, Thunderbird with the ImportExportTools add-on is a solid free option.
But if you need a clean PDF you can share, archive, or print — especially on a Mac where Outlook alternatives are scarce — MSG to PDF is the fastest path from inbox to document.