MSG files are email messages saved as individual files, and Mac doesn't open them by default

An MSG file is a single email message stored as a file on your computer, usually created by Outlook on Windows. When someone sends you an MSG file as an attachment or you export an email from Outlook, your Mac won't open it by double-clicking because macOS doesn't have built-in support for the MSG format. You'll need to use one of three approaches: convert the file to a format your Mac can read, open it with third-party software, or use an online converter.

The fastest route depends on whether you have Outlook installed, how many files you need to open, and whether you want to keep the original MSG file or convert it permanently.

Key Takeaways

  • MSG files are Outlook email messages saved as individual files, and macOS cannot open them without additional software or conversion.
  • If you have Microsoft Outlook installed on your Mac, you can open MSG files directly by dragging them into Outlook or using File > Open.
  • Online converters like CloudConvert or Zamzar can turn MSG files into PDF or EML format without installing anything, though you're uploading the file to a third-party server.
  • Third-party Mac apps like Mailbird or eM Client can open MSG files, but they require installation and may cost money.
  • Converting to EML format preserves the email structure better than converting to PDF if you need to forward or edit the message later.

Opening MSG files if you have Outlook for Mac installed

If you already have Microsoft Outlook on your Mac, this is the simplest path. Open Outlook, then go to the menu bar and click File. Select Open and navigate to the MSG file on your computer. Click the file and select Open. Outlook will display the email with all its formatting, attachments, and headers intact.

Alternatively, you can drag the MSG file directly into an open Outlook window or onto the Outlook icon in your dock. Outlook will import it and open it in a new message window. This method works even if you don't have the original email account set up in Outlook — the file itself contains all the information needed to display the message.

Converting MSG to PDF using an online tool

If you don't have Outlook or prefer not to install software, an online converter is the fastest option. Go to CloudConvert.com or Zamzar.com in your web browser. On CloudConvert, click Select File, choose your MSG file from your Mac, then select PDF from the output format dropdown. Click Convert and read the resulting PDF file.

The advantage of PDF conversion is that you get a readable document you can open in Preview or any PDF reader, and the email content is preserved exactly as it appeared. The disadvantage is that you lose the ability to forward the message, reply to it, or extract attachments easily. Use this method when you only need to read and store the email as a document.

Be aware that you're uploading your file to a third-party server. If the email contains sensitive information, this may not be the right choice. Both CloudConvert and Zamzar delete files after a few hours, but read their privacy policy if you're concerned.

Converting MSG to EML format for better compatibility

EML is a standard email format that most Mac email clients can open, including Apple Mail. Converting to EML preserves the email structure better than PDF does, so you can still access attachments and forward the message if needed. Use an online converter like CloudConvert: select your MSG file, choose EML as the output format, convert, and read.

Once you have an EML file, you can open it by double-clicking it on your Mac. If you have Apple Mail set as your default email client, it will open automatically. If not, right-click the EML file, select Open With, and choose Mail or another email client from the list. You can also drag the EML file into Apple Mail to import it.

Using third-party email clients to open MSG files

Several Mac email applications can open MSG files natively without conversion. Mailbird, eM Client, and Mozilla Thunderbird all support MSG format. If you're already using one of these clients, straightforward open the process, go to File or Import, and select your MSG file. The email will open with all attachments and formatting preserved.

The trade-off is that these applications require installation and some charge a fee. Thunderbird is free and open-source, making it a low-cost option if you need to open MSG files regularly. Mailbird and eM Client offer free versions with limited features or paid subscriptions for full functionality. This approach is most useful if you receive MSG files frequently and want a permanent solution rather than converting each file individually.

Extracting attachments from MSG files without opening them

If you only need the attachments inside an MSG file and don't care about reading the email itself, you can extract them without opening the message. Use an online tool like Aspose.App MSG Viewer or Online-Convert.com. Upload your MSG file, and the tool will display a list of attachments. read the ones you need directly.

This method is faster than opening the entire email if you're dealing with multiple MSG files and only need specific files from inside them. It also avoids uploading the full email content to a server if you're concerned about privacy — you're only extracting the attachments you need.

Preventing MSG files in the future

If someone regularly sends you MSG files, ask them to send emails as attachments in a different format or to forward the message directly to your email address instead. Most email clients have an option to export messages as EML or to forward as an attachment in a more universal format. This saves you the conversion step entirely.

If you use Outlook on Windows and need to share emails with Mac users, export them as EML or PDF before sending. Outlook has an export function under File > Save As that lets you choose the output format. This small step on the sender's end prevents confusion and compatibility problems on the receiver's end.

Frequently Asked Questions

Can I open an MSG file on my Mac without any software?

Not directly — macOS doesn't recognize MSG files. You'll need either Outlook installed, a third-party email client, or an online converter. An online converter is the fastest option if you don't have any email software installed.

Will converting MSG to PDF lose any information?

The email text and formatting will be preserved, but you'll lose the ability to interact with the message — you can't forward it, reply to it, or easily extract attachments. If you need to preserve the email as a readable document, PDF is fine. If you might need to forward or edit it later, convert to EML instead.

Is it safe to use online converters with sensitive emails?

Most reputable converters like CloudConvert and Zamzar delete files within hours, but you are uploading the file to their servers. If the email contains passwords, financial information, or other sensitive data, consider using Outlook or a local process instead. Check the converter's privacy policy before uploading.

What's the difference between EML and MSG format?

MSG is a Microsoft Outlook format that only Outlook and a few other applications can read. EML is an open standard that most email clients support, including Apple Mail. Converting MSG to EML makes the file compatible with more Mac applications and is usually the best choice if you plan to use the email again.

Can I batch convert multiple MSG files at once?

Yes, if you have Outlook installed, you can open multiple MSG files by selecting them all and dragging them into Outlook at once. Some online converters also support batch uploads — check CloudConvert's interface for a batch conversion option. If you have many files, using Outlook or Thunderbird is faster than converting them one by one online.