Stellar Converter for OLM – OLM to PST, Mac Outlook Migration, Mailbox Export

What is included in Stellar Converter for OLM?

OLM to PST – Converts Outlook for Mac mailboxes to PST
Complete Mailbox Items – Emails, attachments, contacts, calendars, tasks, notes
Free Preview – Three-pane preview before you save
Find Feature – Locates OLM files stored on the PC
Core Capacity – Supports OLM from Outlook for Mac 2011–2021
Important – Microsoft 365 export needs the Technician edition

What are the main benefits of Stellar Converter for OLM?

Stellar Converter for OLM is a Windows utility that turns Outlook for Mac (OLM) data files into Outlook-compatible PST and other formats. It moves the complete mailbox — emails, contacts, calendars, tasks, and notes — without altering the original folder structure.

No Data Loss – Keeps folder hierarchy and item metadata intact
Selective Export – Convert only chosen folders or mailbox items
Output Formats – Exports to PST, MSG and EML files
Large Mailboxes – Handles oversized OLM files without size limits
Auto Split – Splits large PST output near 45 GB
Cloud Export – Technician edition exports mailboxes straight to Microsoft 365

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What does Stellar Converter for OLM do?

It converts Outlook for Mac OLM data files into the PST format used by Outlook for Windows, so a Mac mailbox can be opened on a Windows PC. Outlook for Mac stores mail in the OLM format and Microsoft provides no built-in way to turn that into PST, which is why a dedicated converter is needed. The tool extracts emails, attachments, contacts, calendars, tasks, and notes while rebuilding the exact folder tree. The Standard edition also writes to MSG and EML; the Technician edition adds PDF, HTML, RTF, and direct Microsoft 365 export.

Who should use Stellar Converter for OLM?

It fits anyone moving from Outlook for Mac to Outlook on Windows or to Microsoft 365. The Standard edition suits a single user converting one mailbox to PST, while an administrator handling several user mailboxes or needing PDF and Office 365 output should pick the Technician edition. Because it reproduces the original folder structure exactly, it is also useful when an archived OLM file has to stay readable long after the Mac that created it is gone. That keeps old correspondence searchable in Windows Outlook without rebuilding folders by hand.

What is the difference between the Standard and Technician editions?

Both editions convert OLM mailboxes to PST, MSG, and EML and both let you preview every item before saving. The Technician edition adds three capabilities: output to PDF, HTML, and RTF; direct export to a Microsoft 365/Office 365 account; and handling suited to multiple mailboxes. Choose Standard for a plain OLM-to-PST conversion, and Technician when you need the extra file formats or a cloud destination. The table below shows the verified differences.

Which Outlook for Mac versions and file sizes does it support?

It converts OLM files created by Outlook for Mac 2011, 2016, 2019, and 2021, and the resulting PST opens in current and older Outlook for Windows releases. There is no fixed file-size cap, so large or archived OLM mailboxes convert in a single pass instead of forcing you to split the source first. To keep the result stable in Outlook, oversized PST output can auto-split at roughly 45 GB, an option you can switch off under the advanced settings. This matters when you migrate years of accumulated mail that would otherwise produce one unwieldy PST.

Does Stellar Converter for OLM export directly to Microsoft 365?

Direct export to a Microsoft 365/Office 365 account is available only in the Technician edition, not in Standard. The Standard edition writes the converted mailbox to a PST, MSG, or EML file that you then import into Outlook yourself. If the goal is to move a Mac mailbox straight into a Microsoft 365 account without an intermediate PST import, the Technician edition is the one to buy. Choosing Standard for that workflow would leave you with a PST file and an extra manual import step.

What should you check before converting an OLM file?

Confirm your source is a genuine .olm export from Outlook for Mac, since the tool reads that specific format rather than mailbox databases from other Mac mail clients. Decide your output format up front, because moving to PDF, RTF, or Microsoft 365 later means stepping up to the Technician edition. Run the free demo first: it scans the file and shows every email, contact, and calendar entry in a three-pane preview, so you can verify the conversion is complete before paying. That preview step is the practical way to catch a corrupt or partial OLM file before committing to the full version.