The short answer: .msg files are Outlook email format, and Mac doesn't open them natively

A .msg file is a single email message saved in Microsoft Outlook's proprietary format. It contains the email text, attachments, and metadata all bundled together. On Windows, Outlook opens these when ready. On a Mac, you have no built-in way to read them — Mac Mail doesn't recognize the format, and neither does any other Apple app.

You have three realistic routes: convert the file to a format your Mac can read, use an online converter, or install software that handles .msg files. Which one works depends on whether you have Outlook, how many files you need to open, and whether you want to keep the original file intact.

Key Takeaways

  • Mac Mail and other Apple apps cannot open .msg files directly, so you need either Outlook, a conversion tool, or an online service.
  • If you have Microsoft 365 or Outlook for Mac installed, opening the file is one click — Outlook handles it natively.
  • Free online converters like CloudConvert or Zamzar can turn a .msg file into .pdf or .eml format in minutes, though you upload your file to their server.
  • Third-party Mac apps like Mailstrom or MSG Viewer exist but cost money and are worth it only if you open .msg files regularly.
  • Converting to .eml format preserves the email structure and lets you import it into Mail or other Mac email clients.

Using Outlook for Mac if you already have it installed

If you have Microsoft 365 or a standalone copy of Outlook for Mac, this is the simplest path. Double-click the .msg file, and Outlook opens it directly. You can read the full email, open attachments, and forward it if needed. The file stays in its original format — nothing converts or changes.

Check whether you have Outlook by opening Applications and looking for Microsoft Outlook. If it's there, you're done: just double-click any .msg file and it will open. If you don't have it and don't want to buy it, skip to the next section.

Converting .msg files to .pdf or .eml online

Online converters let you upload a .msg file and read it in a different format without installing anything. CloudConvert and Zamzar are the two most reliable free options. Both let you convert to .pdf (which any Mac can read) or .eml (which Mac Mail and most other email clients can import).

To use CloudConvert: go to cloudconvert.com, click "Select File", choose your .msg file, select the output format (.pdf or .eml), and click "Convert". The converted file downloads to your Downloads folder. The process takes under a minute for most files.

The trade-off is privacy: you're uploading your email to a third-party server. If the email contains sensitive information, passwords, or financial details, this route is not safe. For routine emails or files you don't mind sharing, it's fast and free. Both services delete files after a few hours, but that's not a may provide.

Importing .eml files into Mac Mail after conversion

If you convert a .msg file to .eml format, you can import it into Mac Mail so it sits in your mailbox like a normal email. Open Mac Mail, go to File menu, select "Import Mailboxes", choose "Files" as the source, and navigate to your .eml file. Mac Mail imports it into a folder you name, and you can read it, search it, and organize it like any other message.

This works well if you need to keep the email long-term or want to file it with other messages. The downside is that .eml import can sometimes lose formatting or attachments, depending on how complex the original email was. For plain text emails or straightforward messages, it works reliably.

Using a dedicated Mac app for .msg files

Apps like Mailstrom, MSG Viewer, and Outlook Import Assistant are built specifically to open .msg files on Mac. Most cost between $5 and $30 and work by letting you drag and drop a .msg file into the app, which then displays it. Some also let you export to other formats or batch-convert multiple files at once.

These are worth considering only if you regularly receive .msg files — say, more than once a week. For occasional use, the free online converters or Outlook itself are faster and cheaper. If you do buy one, read the reviews on the Mac App Store first, because quality varies widely and some apps have bugs with certain email types.

What to do if the file won't open or looks corrupted

Sometimes a .msg file refuses to open or displays garbled text. This usually means the file was damaged during read or email transfer. Try downloading it again from the source, or ask the person who sent it to resend it. If it still fails, try converting it with a different online service — some converters handle corrupted files better than others.

If the file opens but attachments are missing, that's often a sign the email was forwarded or saved incorrectly on the Windows side. There's no fix on your end; you'd need to ask the sender for the original email or the attachment separately.

Frequently Asked Questions

Can I just rename a .msg file to .eml and open it?

No. Renaming the file extension doesn't change what's inside — it just confuses your Mac about what app to use. The file structure is different between formats, so Mac Mail won't read it. You need to actually convert the file using a tool or service.

Is it safe to use free online converters with work emails?

It depends on what's in the email. If it contains passwords, financial information, or confidential company data, uploading to a third-party server is risky. For routine emails or files you don't mind being seen, the risk is low — both CloudConvert and Zamzar use encryption during upload. When in doubt, ask your IT department what's allowed.

Why does Windows have .msg files but Mac doesn't use them?

Outlook is a Windows program first, and .msg is Microsoft's proprietary format. Mac Mail uses standard formats like .eml that work across different email clients. When Outlook for Mac exists, it's a separate program that happens to read .msg files, but it's not the default Mac email format.

Can I open a .msg file in Gmail or another web email service?

Not directly. Gmail, Yahoo Mail, and Outlook.com don't recognize .msg format. You'd need to convert it to .eml first, then import it. Some web services let you upload .eml files and add them to your inbox, but the process varies by service.

What if I receive .msg files all the time from my job?

If this is regular, buying Outlook for Mac or a dedicated .msg app makes sense — it's faster than converting each file individually. Microsoft 365 for Mac costs about $70 per year and gives you Outlook plus Word, Excel, and other apps. A standalone .msg viewer app costs $5 to $20 one-time. Either way, you save time if you're opening these files weekly.