TL;DRScanpst rebuilds your folders under Recovered Personal Folders, and Microsoft says those folders are usually empty. The recovered items sit in a Lost and Found folder, and anything still missing may only exist in the .bak file saved next to the original.
One user on Microsoft Q&A wrote that the file finally opened, but every subfolder and its content were missing. Microsoft explains that the rebuilt folders start empty and the recovered items go elsewhere.
- Expand the repaired data file in Outlook and open Lost and Found. Messages the repair could not place back into their folder end up here.
- Create a new, empty PST and drag the items you need from Lost and Found into it.
- Still missing something? Take the .bak file, copy it, rename the copy to .pst and bring it in with the Import and Export Wizard.
The .bak is the original corrupted file, so it often holds nothing beyond what Lost and Found already shows. It is still worth checking, and it holds the original file only if a later pass has not overwritten it.
How to open the repaired PST file in Outlook
TL;DROpen the repaired copy with File > Open & Export > Open Outlook Data File, then drag the mail where you need it. If Outlook keeps failing with the same profile, set up a new Outlook profile and point it at the repaired file.
Outlook still points at the old path. You can attach the repaired file or use a fresh profile.
In Outlook choose File > Open & Export > Open Outlook Data File and select the repaired copy. It appears as a separate set of folders in the navigation pane, and you can drag messages into your main mailbox. A new PST saved by our repair tool opens the same way.
For POP and IMAP accounts, where the PST is the mailbox, a new Outlook profile that uses the repaired file rules out a damaged profile as the cause. Use Import/Export > Import from another program or file > Outlook Data File (.pst) to merge it into the new profile's file.
No working Outlook on this PC? You can still open a PST file without Outlook to read and export the messages.
Scanpst did not fix it: what should you try next?
TL;DRAfter three passes on a local copy, extra passes rarely change the result. The next steps, from cheapest to most thorough, are the .bak file, a new profile, and a read-only repair tool.
In one Slipstick thread, Outlook 2010 still refused the file after a repair, and the MVP's answer was to try a third time and, if that fails, see if a commercial program could access it.
| Method | Writes to the original? | Needs Outlook? | Deleted mail | Cost |
|---|
| scanpst.exe | Yes, rewrites in place (.bak kept) | Yes | No | Free with Outlook |
| PST Repair Tool for Outlook | No, read-only, saves a new file | No | Deep scan, often [partial] | Free scan and preview; license to save |
| .bak import | No | Yes | No | Free |
| New Outlook profile | No | Yes | No | Free |
| Rebuild the OST from the server | Replaces the cache file | Yes | Only what the server still has | Free |
✔️ Try first.
Run scanpst on a local copy, then check Lost and Found. For the minor errors most PSTs carry, that is enough.
✔️ Try next.
Import the .bak copy, or open the repaired file in a new profile. Both cost nothing and leave the original alone.
✔️ Last resort.
Open a fresh copy of the damaged file in a read-only repair tool, check what the preview shows, and save only if it holds the mail you need.
Does scanpst have a file size limit?
TL;DRMicrosoft documents no size limit for scanpst itself. The 2 GB figure many repair guides quote belongs to the old ANSI PST format, capped at 1.933 GB by default, while current Unicode PST files default to a 50 GB maximum.
50 GB
default maximum size of a Unicode PST or OST file in Outlook 2010 and later; Outlook stops adding new data to the file at 47.5 GBSource
1.933 GB
default cap of an old ANSI PST file; Microsoft keeps ANSI files under 2 GB to prevent corruptionSource
Microsoft's page on size limits for Outlook data files gives these defaults.
| PST format | Default maximum | New data stops at |
|---|
| Unicode, Outlook 2010 and later | 50 GB (51,200 MB) | 47.5 GB (48,640 MB) |
| Unicode, Outlook 2007 and 2003 | 20 GB (20,480 MB) | 19 GB (19,456 MB) |
| ANSI (old format) | 1.933 GB | 1.816 GB |
"scanpst cannot handle files over 2 GB" refers to ANSI files, a format current Outlook versions no longer create by default. A large Unicode file is slower to scan, which explains the half-hour estimates. If your file is an ANSI leftover close to 2 GB, Outlook may refuse to open it or write to it.
Old registry tweaks that raise these limits are less reliable than they used to be: a 2025 comment on Microsoft Q&A notes that a current Microsoft 365 build had no such key. Trimming the file is the safer route.