Convert an Apple Mail MBOX export to Outlook PST

Q: What does Apple Mail export?

The Mailbox → Export Mailbox command saves an MBOX package containing your email. Copy the whole package when moving it to Windows; do not rename or rearrange the files inside.

Before you start

Apple Mail creates the source on your Mac, and the MBOX to PST converter creates the Outlook file on Windows. MBOX is a mailbox format that can hold many messages; PST is the data-file format used by classic Outlook. The Windows computer must have supported classic Outlook, the desktop app with a File tab. New Outlook cannot run this converter.

In Apple Mail, open a few older messages and attachments to make sure they have downloaded from the mail provider. You will also need enough storage for the original export, a Windows working copy, and the resulting PST. See the Windows and classic Outlook requirements before transferring a large mailbox.

Step 1. Export the mailbox from Apple Mail

In Apple Mail, select one or more mailboxes and choose Mailbox → Export Mailbox. Choose a destination with enough free space and wait for the export to finish. Apple creates an MBOX package; keep the package and the files inside it together.

Step 2. Back up the export and note its folders

Copy the complete exported package to backup storage before converting it. Keep a simple note of the mailbox names and total export size so you can recognize the source and compare its folder layout with Outlook later.

Step 3. Transfer a working copy to Windows

Copy the complete package to the Windows computer without changing its internal folders or filenames. Use this Windows copy as the converter input and leave the Mac export or backup unchanged in case you need to repeat the conversion.

Step 4. Convert the MBOX data to PST

Install the MBOX to PST converter. Our installer includes Convert MBOX to PST as part of ReliefJet Essentials. Open the utility from the standalone ReliefJet Essentials launcher or the ReliefJet tab in classic Outlook.

Select the copied MBOX file or the parent folder, choose a path and filename for the new PST, and enable Include subfolders when the export contains a folder tree. Click Run and wait for the conversion report.

Step 5. Open and verify the PST

In classic Outlook, choose File → Open & Export → Open Outlook Data File and select the new PST. Confirm that the expected folders appear, then open an old message, a recent message, and several attachments or inline images. Keep the original MBOX export until the PST has passed these checks and has its own backup copy. The full verification checklist covers larger or business-critical mailboxes.

What this route does not move automatically

MBOX contains email messages, not the rest of your Apple Mail or Mac setup. Rules, account settings, signatures, contacts, calendars, and Keychain credentials need separate migration steps. The converter is a Windows application and does not run inside Apple Mail or on macOS.

Primary sources

FAQ

Can I run the converter on a Mac?

No. Export your mailbox from Apple Mail, then copy the complete export to a Windows computer with classic Outlook installed. Run the conversion there.

What does Apple Mail export?

The Mailbox → Export Mailbox command saves an MBOX package containing your email. Copy the whole package when moving it to Windows; do not rename or rearrange the files inside.

Are contacts and calendars included?

No. An Apple Mail export contains email. Export your contacts and calendars separately if you also want those in Outlook. Mail rules, account settings and signatures are separate too.