Microsoft Plans to Add PST Offline Data File Support to New Outlook Version, Including Import and Export Functions

According to Microsoft's plans, the company will automatically switch Microsoft 365 enterprise subscription users to the new version of Outlook based on WebView 2 Runtime in April 2026. The current UWP version of the mail application has already been discontinued.

However, the new version of Outlook lacks one of the key features: PST offline data files. PST is a proprietary data format developed by Microsoft that can import and export Outlook data, such as emails, contacts, calendar items, tasks, and notes.

Due to the absence of PST offline data file support in the new version of Outlook, users have encountered various inconveniences. Therefore, Microsoft has decided to introduce PST support to the new version of Outlook. Originally, this feature was scheduled to launch in November but was delayed due to development planning issues.

Microsoft states in Microsoft 365 Roadmap ID 399467:

The first phase of PST support in the new Windows Outlook: providing read-only access to email items in PST files. Users will be able to open PST files, read emails in PST files, and search for emails within PST files. All calendar, contact, and task data stored in PST files will still be present but inaccessible in this preview version, with expanded PST support planned for the next release.

In Microsoft 365 Roadmap ID 405754, Microsoft indicates:

Support for importing and exporting data in Outlook: This feature will add support for importing PST files into Outlook for Mac, and support for OLM data files will include importing and exporting data.

This means that future versions of Outlook for Windows and Mac will support PST-related features, at the very least allowing users to quickly read data content and perform data import or export operations via PST files.

According to Microsoft's planned roadmap IDs, this is expected to be achieved by January 2025. Microsoft may initially roll out the feature to preview users for testing, and after testing is complete, it will be pushed to official users. At that time, users in need will be able to perform various operations through PST files.