PST files in the new Outlook for Windows

Microsoft is replacing classic Outlook for Windows with the new Outlook (the app that also replaced Mail and Calendar). Classic Outlook opens and imports PST files freely; the new Outlook’s support is partial and still changing.

What the new Outlook can do with PST files

According to Microsoft’s support pages, the new Outlook can open a PST and read its mail, under conditions:

• classic Outlook must also be installed on the same PC, with the same architecture (both 32-bit or both 64-bit);
• the account in the new Outlook needs a Microsoft 365 subscription;
• it does not work on the ARM version of the new Outlook, or in safe or recovery mode.

Importing a PST (copying its mail into your mailbox) is still done in classic Outlook. Microsoft has said it plans to remove the need for classic Outlook and to add import, but those changes are not released at the time of writing. Users also report that calendar items and contacts in a PST are not reachable from the new Outlook.

Because this changes over time, check Microsoft’s article Open and find items in an Outlook Data File (.pst) for the current state.

Your options today

Just read the old mail. Open the PST in our PST Viewer. It needs neither Outlook version nor an account, and runs on any computer.

Bring the mail into your Microsoft 365 mailbox. Use classic Outlook’s File › Open & Export › Import/Export › Import from another program or file › Outlook Data File (.pst). If classic Outlook is not available, open the PST in the new Outlook (with the conditions above) and drag folders into your mailbox.

The PST is too large or damaged. Very large archives are slow to open and to import. Split it by year first, or run the free health check if Outlook reports errors.

Moving away from Outlook altogether. Convert the PST to MBOX for Thunderbird or Apple Mail, or to EML files.

Frequently asked

Will my PST files stop working? The files themselves keep working: the format is documented and many tools read it. What changes is which version of Outlook opens them.

Is there a PST viewer for the new Outlook? The new Outlook has no separate viewer. A browser-based viewer opens PST files without any version of Outlook.