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OLM PST

Convert OLM to PST
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Convert Outlook for Mac OLM files to Windows PST format. Migrate from Mac to Windows Outlook seamlessly. EU servers, GDPR compliant.

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What is a OLM file?

OLM (Outlook for Mac) is the archive format used exclusively by Microsoft Outlook on macOS. When you export data from Outlook for Mac, it creates an .olm file containing emails, contacts, calendar items, tasks, and notes.

Key facts about OLM:
- Mac-only format — created and read only by Outlook for Mac (2011, 2016, 2019, Microsoft 365 Mac)
- ZIP-based structure — internally, an OLM file is a ZIP archive containing XML and EML files
- Full data export — includes emails, calendar, contacts, tasks, and notes
- No Windows support — Outlook for Windows cannot open .olm files

OLM files become relevant when:
- Switching from Mac to Windows
- Migrating from Outlook Mac to a new machine
- Archiving Mac email data for enterprise compliance
- Sharing email data between Mac and Windows users

What is a PST file?

PST (Personal Storage Table) is the universal Outlook archive format, supported by all versions of Outlook for Windows and importable by many third-party tools. It's the industry standard for email archiving and cross-platform migration.

By converting OLM to PST, you get:
- Windows compatibility — open in any version of Outlook for Windows
- Full data preservation — emails, calendar, contacts, and attachments
- Searchable archive — Outlook indexes PST for instant search
- Enterprise compliance — PST is the standard for eDiscovery and legal holds

Why convert OLM to PST?

OLM to PST conversion is critical for Mac-to-Windows email migration:

1. Switching from Mac to Windows
The most common scenario: you or your organization are moving from Mac to Windows. Outlook for Mac exports OLM, but Outlook for Windows needs PST. Direct import is impossible without conversion.

2. Enterprise standardization
Companies standardizing on Windows need to migrate Mac users' email archives. OLM to PST conversion ensures all email data is in a unified, Windows-compatible format.

3. Cross-platform collaboration
When Mac and Windows users need to share email archives, PST is the common ground. OLM files are unreadable on Windows.

4. Backup and archiving
PST is more widely supported for long-term archiving. Converting OLM to PST creates a portable backup accessible on any platform with Outlook.

OLM vs PST — Key Differences

Feature OLM PST
Platform macOS only Windows (all versions)
File structure ZIP archive with XML + EML Binary database (B-tree)
Created by Outlook for Mac (export) Outlook for Windows
Email clients Outlook for Mac only Outlook for Windows, third-party tools
Data types Emails, calendar, contacts, tasks Emails, calendar, contacts, tasks
Max file size No hard limit 50 GB (Outlook 2010+)
Industry adoption Limited to Mac users Universal standard for archiving
eDiscovery support Limited tool support Full industry support

3 methods to convert OLM to PST

Method 1: IMAP intermediary (manual)

Add an IMAP account (like Gmail) to Outlook Mac, copy all emails there, then access the same IMAP account from Outlook Windows and export to PST.

Pros

  • ✓ Free (uses existing email accounts)
  • ✓ Preserves folder structure

Cons

  • ✗ Very slow (upload then download all emails)
  • ✗ Requires both Mac and Windows
  • ✗ May hit IMAP storage limits
  • ✗ Calendar and contacts not transferred
  • ✗ Complex multi-step process

Method 2: Desktop conversion software

Several desktop applications can convert OLM files to PST locally on Windows. These paid tools typically cost between $39 and $149 per license.

Pros

  • ✓ Direct conversion
  • ✓ Handles contacts and calendar

Cons

  • ✗ Expensive ($39-$149)
  • ✗ Requires a Windows machine to run
  • ✗ Installation required
  • ✗ Slow for large archives
Recommended

Method 3: MailtoPst (online, free trial)

Upload your OLM file from your Mac directly to MailtoPst. No Windows machine needed — convert in the cloud and download the PST on your new Windows PC.

Pros

  • ✓ First conversion free
  • ✓ No Windows needed for conversion
  • ✓ Works directly from Mac browser
  • ✓ Preserves emails, calendar, contacts
  • ✓ GDPR compliant, EU servers

Cons

  • ✗ Requires internet connection
  • ✗ Paid credits after first conversion
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Step by step

How to convert OLM to PST with MailtoPst

01

Upload your OLM file

Drag & drop or click to upload your .olm file. Files up to 51 GB supported with resumable upload.

02

Choose PST as output

Select PST from the format dropdown. MailtoPst auto-detects the best conversion settings.

03

Download your PST file

Conversion takes seconds. Download your .pst file or receive it by email.

Convert your OLM to PST now →

First conversion free. No credit card required.

FAQ

Frequently Asked Questions

Can I convert OLM to PST without a Windows computer?

Yes! MailtoPst is a web-based tool. Upload your OLM file from your Mac's browser, and download the PST when it's ready. You only need Windows when you want to open the PST in Outlook.

Will my calendar events transfer from OLM to PST?

Yes. MailtoPst preserves calendar events, contacts, tasks, and notes during OLM to PST conversion, not just emails.

How do I export an OLM file from Outlook for Mac?

In Outlook for Mac: go to Tools > Export, select the items you want to export (mail, contacts, calendar), choose 'Outlook for Mac archive (.olm)', and click Continue. The OLM file will be saved to your chosen location.

Is OLM to PST conversion free?

Your first conversion is free with no credit card required. After that, credit packs start from €4.99.

What versions of Outlook for Mac support OLM export?

OLM export is available in Outlook for Mac 2011, 2016, 2019, and Microsoft 365 for Mac. The new Outlook for Mac (2023+) may use different export methods.

Related conversions

EML → PST EMLX → PST MBOX → PST OST → PST PST → MBOX
See all 30 conversion paths →

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