How to Migrate From Outlook to Apple Mail on Mac

Why Move From Outlook to Apple Mail

Apple Mail is the default email client on macOS, and for many Mac users, it is the most natural choice for everyday email. It integrates seamlessly with the rest of the Apple ecosystem, including iCloud, Contacts, Calendar, Spotlight search, and Focus modes. Notifications, gestures, and keyboard shortcuts all follow the conventions that Mac users already know.

Several practical reasons lead people to abandon Outlook in favor of Apple Mail. The most common is the end of a Microsoft 365 subscription. Once the subscription lapses, Outlook for Mac becomes read-only, pushing users toward an alternative. Others switch when they realize they only use Outlook for email and do not need its calendar, contacts, or task features — all handled by native macOS applications.

Performance is another factor. Outlook for Mac consumes more memory and CPU than Apple Mail. On older MacBooks or machines with limited RAM, the difference is noticeable.

Whatever the reason for switching, the migration challenge comes down to one thing: getting your email data out of Outlook’s format and into something Apple Mail can use.

Understanding the Format Gap

Microsoft Outlook stores email data in PST (Personal Storage Table) files on Windows and OLM (Outlook for Mac) files on macOS. Neither format is recognized by Apple Mail.

Apple Mail stores its messages as individual EMLX files on disk, but it can import mailbox data from MBOX files. MBOX is a widely supported, text-based format that serves as a common bridge between email clients.

The migration path therefore runs through MBOX: you convert your Outlook data to MBOX format, and then import those MBOX files into Apple Mail. This two-step process ensures that your messages, attachments, and folder organization arrive intact.

Step 1: Export Your Outlook Mailbox as PST

If you are migrating from Outlook on Windows, you need to export your mailbox as a PST file. If you already have a PST file (from a previous backup or archive), you can skip this step.

In Outlook for Windows, go to File > Open & Export > Import/Export. Select Export to a file, then choose Outlook Data File (.pst). Select the top-level mailbox to include all folders, or pick individual folders if you only need to migrate specific ones. Choose a save location and complete the export.

Transfer the resulting PST file to your Mac using a USB drive, network share, or AirDrop. If your email is in a Microsoft 365 cloud mailbox and you do not have Outlook for Windows available, ask your IT administrator to perform a PST export using the Microsoft 365 compliance tools.

Step 2: Convert PST to MBOX Online

With your PST file on your Mac, open Safari or any browser and go to the PST to MBOX converter on mailtopst.com. Upload your PST file by dragging it into the upload area.

MailtoPst processes the conversion entirely in the cloud, so there is no software to install on your Mac. It accepts PST files from all Outlook versions, including both the older ANSI format and the modern Unicode format. The converter parses the entire folder structure, extracts every message with its headers, body content, and attachments, and produces MBOX files that mirror your original mailbox organization.

Every new account receives 100 MB free credit. For larger mailboxes, pay-as-you-go pricing applies with no subscription. Once processing is complete, download the converted files. If your PST contained multiple folders, you will receive a ZIP archive containing one MBOX file per folder.

For additional context on working with PST files on a Mac, see our guide on how to open a PST file on Mac.

Step 3: Import MBOX Into Apple Mail

Apple Mail includes built-in support for importing MBOX files, so no additional software is required.

Open Apple Mail on your Mac. Go to File > Import Mailboxes. In the dialog that appears, select Files in mbox format and click Continue. Navigate to the folder where you saved your converted MBOX files, select them, and click Choose.

Apple Mail will import each MBOX file and place the messages under a new Import folder in the sidebar. The import may take a few minutes depending on the number of messages and attachments. Once complete, you can review the imported messages and then drag them into the appropriate mailbox folders in your account (Inbox, Sent, or any custom folders you want to organize them into).

If you prefer to keep the imported messages in local storage rather than moving them to an IMAP account, they will remain accessible under the On My Mac section in Apple Mail’s sidebar.

Verify the Import

Open several messages across different folders to confirm that:

• Dates, senders, and recipients are displayed correctly
• HTML email formatting is preserved
• Attachments are present and can be opened
• Inline images display properly within the email body

If your original PST contained thousands of messages, Apple Mail’s Spotlight indexing may take some time to complete after the import. Search results will improve as indexing finishes in the background.

Migrating From Outlook for Mac (OLM Files)

If you have been using Outlook for Mac rather than Outlook for Windows, your email data is stored in OLM format rather than PST. OLM is Outlook for Mac’s proprietary archive format.

To export an OLM file from Outlook for Mac, go to Tools > Export. Select the items you want to export (Mail, Contacts, Calendar, etc.) and save the OLM archive.

MailtoPst supports OLM files as well. Upload your OLM file to the converter, select MBOX as the output format, and follow the same import process described above for Apple Mail. The folder structure and message data are preserved just as they are with PST conversion.

This is particularly useful when moving away from Outlook for Mac after a subscription ends, since OLM files cannot be opened by any other application.

Contacts and Calendars

Email messages are the core of most migrations, but contacts and calendar events are often important too. These data types require separate handling because they are not included in the MBOX email conversion.

Contacts

In Outlook for Windows, export your contacts via File > Open & Export > Import/Export > Export to a file > Comma Separated Values (.csv). Transfer the CSV to your Mac and import it in the Contacts app using File > Import. From Outlook for Mac, you can drag contacts directly into the macOS Contacts app.

If your contacts are in a Microsoft 365 or Exchange account, adding your Microsoft account under System Settings > Internet Accounts will sync contacts automatically.

Calendars

Export your Outlook calendar as an ICS file. In Outlook, right-click on your calendar and look for a save or export option, or use the File > Save Calendar feature. Transfer the ICS file to your Mac and open it with the Calendar app, which will offer to import the events.

As with contacts, if your calendar is in Microsoft 365 or Exchange, adding the account to macOS will sync events automatically.

Preserving Folder Organization

One concern during migration is maintaining the folder structure you built over years of email organization. MailtoPst preserves the folder hierarchy from your PST or OLM file when generating MBOX output. Each folder and subfolder in Outlook produces a corresponding MBOX file.

When you import these MBOX files into Apple Mail, they initially land under the Import folder. To recreate your original organization:

1. Create the folder structure you want under your email account or under On My Mac in Apple Mail’s sidebar
2. Select the messages from each imported folder
3. Drag them into the corresponding destination folder

For mailboxes with many folders, this reorganization step takes a bit of time but ensures proper organization going forward. If you had nested subfolders in Outlook (for example, Projects > Client A > 2025), the MBOX files from MailtoPst will reflect that nesting, and you can recreate the same hierarchy in Apple Mail.

Additional Considerations

Search and Spotlight

One of Apple Mail’s strengths is its integration with Spotlight. After importing your messages, Spotlight will index the content in the background, making every email searchable from the macOS menu bar. This indexing process may take a few hours for large mailboxes but requires no action on your part.

Rules and Filters

Email rules created in Outlook do not transfer to Apple Mail. You will need to recreate any message filtering rules using Apple Mail’s Preferences > Rules section. The rule system in Apple Mail supports conditions based on sender, subject, recipient, and message content, covering most common filtering needs.

Storage Considerations

Imported emails stored locally (under On My Mac) count against your Mac’s disk space. If you are migrating a very large archive, ensure you have sufficient storage, or move imported messages to an IMAP account so they are stored on the server.

For users who may need to convert in the opposite direction, our guide on converting EMLX to PST covers that workflow. See also the Apple Mail to Outlook use case page.

Make the Switch

Migrating from Outlook to Apple Mail is a well-defined process: export your Outlook data as PST (or OLM), convert it to MBOX using MailtoPst’s online converter, and import the MBOX files into Apple Mail. Your emails, attachments, and folder structure transfer cleanly, and the entire process can be completed in under an hour for most mailboxes.

Once your messages are in Apple Mail, you gain the benefits of native macOS integration, lower resource usage, and a streamlined interface designed for the platform you are already using.

Convert now — upload your PST file and get MBOX files ready for Apple Mail in minutes.