For personal or professional reasons, a lot of people switch from Outlook for Mac to Outlook for Windows. A common problem that comes up during this process is that users can't get to their Mac Outlook mailbox on a Windows computer. Outlook for Mac saves mailbox data in the OLM file format, while Outlook for Windows saves it in the PST file format. Windows Outlook can't open OLM files directly because of this difference.

Your data will be saved in an OLM file if you exported your mailbox from Outlook for Mac. It won't open in Windows Outlook when you try. You need to change the OLM file into PST format before you can read Mac Outlook emails in Windows Outlook.

This guide will show you how to open Mac Outlook OLM files in Windows Outlook, explain why this problem happens, and give you tips on how to safely access your mailbox data.

What does an OLM file do in Outlook for Mac?

An OLM file is a file that Outlook for Mac uses to save mailbox data that has been exported. Outlook for Mac saves data in the OLM format when users back up their Outlook mailbox or want to move data to another computer.

An OLM file could have different kinds of Outlook mailbox data, such as:

• Email
• Attachments
• Contact
• Calendars
• Things to do
• Notes

When people want to back up their Outlook data, move emails to another system, or switch from Mac Outlook to Windows Outlook, they often export OLM files.

The biggest problem with OLM files is that you can only open them in Outlook for Mac.

Why You Can't Open an OLM File from Mac Outlook in Windows Outlook

The main reason for this problem is that Outlook on Mac and Windows use different file formats.

Supported Data File for Outlook

Outlook Version Supported Data File

Outlook for Mac - OLM File

Outlook for Windows - PST File

Windows Outlook can't open OLM files directly because it only works with PST files. Windows Outlook won't recognize an OLM file if you try to import it.

So, to open a Mac Outlook OLM file in Windows Outlook, you need to change the file from OLM to PST format first.

Ways to open a Mac Outlook OLM file in Windows Outlook

In Windows Outlook, there are two common ways to open or access OLM files:

1. How to Move Mac Outlook Emails to Windows Outlook Manually
2. Direct Way to Convert OLM File to PST Format

Users can get to your mailbox data with either method, but the steps and results are different.

Method 1: Open Mac Outlook OLM File in Windows Outlook by Manually

Using an IMAP email account to send emails is the manual way. This lets Outlook for Mac and Outlook for Windows sync mailbox data using an email server.

Step 1: Add the OLM file to Outlook for Mac

Import the OLM file into Outlook for Mac first.

Steps

1. Launch Outlook for Mac.
2. In the menu, click on File.
3. Choose Import.
4. Select the Outlook for Mac archive file (.olm).
5. Look through your files and choose the OLM file.
6. Press Import.

After you finish these steps, all of the emails and mailbox data from the OLM file will show up in Outlook for Mac.

Step 2: Set up an IMAP email account in Outlook for Mac

Next, you need to set up an IMAP email account, like Gmail.

Steps

1. Open Outlook for Mac and click on Tools.
2. Click on Accounts.
3. Choose Add Account.
4. Type in your email address and password.
5. Set up the account with IMAP settings.

Outlook will make folders for that mailbox after you add the account.

Step 3: Put OLM emails in the IMAP mailbox

You need to move emails from the OLM mailbox you imported to the IMAP mailbox now.

Steps

1. Open the folder for the OLM mailbox you imported.
2. Choose the emails you want to move.
3. Put them in the IMAP folder by dragging and dropping them.
4. Let Outlook sync the emails with the server.

The emails will be on the email server once the synchronization is done.

Step 4: Open Mac Outlook emails in Windows Outlook

You can now read the same emails in Windows Outlook.

Steps

1. Start Outlook for Windows.
2. Include the same email account for IMAP.
3. Outlook will start to sync emails from the server.
4. When the sync is done, your emails will show up in Windows Outlook.

The Manual Method for Opening OLM Files Has Some Drawbacks

This method is free, but it has some problems.

• It mostly just sends emails.
• Contacts and calendars might not move over correctly.
• For large mailboxes, the process is slow.
• Needs work by hand.
• During migration, the folder structure may change.

Many users prefer a direct conversion method because of these problems.

Method 2: Change the Mac Outlook OLM file to a Windows Outlook PST file

Using a professional conversion tool to change the OLM file into PST format is the easiest and most reliable way to open Mac Outlook OLM files in Windows Outlook. A GainTools OLM to PST Converter looks through the OLM file and changes all of the mailbox data into PST format while keeping the original folder structure.

How to Change an OLM File to a PST File

The process is easy and usually only takes a few steps.

1. Set up the OLM to PST converter tool and open it.
2. Choose the OLM file and click Add OLM File.
3. The software will look through and load the mailbox data.
4. Look at emails and folders in your mailbox.
5. Select PST as the format for the output.
6. Choose the place you want to go.
7. To start the conversion process, click Convert.

When the process is done, the tool will make a PST file that has all of the Outlook data in it.

How to Add a Converted PST File to Windows Outlook

You can easily open the OLM file in Windows Outlook after it has been changed to PST format.

Steps

1. Start Microsoft Outlook for Windows.
2. Click on File.
3. Choose Open & Export.
4. Press Import/Export.
5. Select Import from a file or program.
6. Choose the Outlook Data File (.pst).
7. Look through the converted PST file and choose it.
8. Click on Finish.

When you import the PST file, all of the emails, contacts, calendars, and attachments from the OLM file will show up in your Outlook mailbox.

Conclusion

You need to change the Mac Outlook OLM file into PST format before you can open it in Windows Outlook. This is because Windows Outlook does not support OLM files. Some emails can be moved using manual methods like IMAP synchronization, but they are slow and not very useful.

Usually, the best way to convert OLM to PST is to do it directly. Once the OLM file is in PST format, users can easily import it into Windows Outlook and get to their emails, contacts, calendars, and attachments without any problems.

You can open Mac Outlook OLM files in Windows Outlook and keep working with your mailbox data without any problems if you follow the steps in this guide.