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📧 After Conversion

After Conversion Import the PST and Verify Every Folder Count

A conversion is not finished when the PST file appears. It is finished when the PST is open in Outlook and you have counted the folders and found everything present. This last page is the difference between a rescue you believe in and one you merely hope worked.

✍️ Technical Anshu📧 Microsoft Outlook⏱️ 7 minute read
🎥 Watch the video for the conversion itself - this page is the quality check that follows it

Two habits separate careful technicians from lucky ones: they bring the data in the right way, and they verify before deleting anything. Below is both - the choice between opening and importing a PST, the duplicate question the wizard asks and what each answer really does, and a five-minute count check that catches the classic losses: an unexported calendar, a folder that stopped mid-way, mail from only one year.

Verification - folder counts, source beside result (example numbers)_ □ X
Inbox4,213 in OST - 4,213 in PST
Sent Items1,870 - 1,870
Projects 2023642 - 642
CalendarPresent, oldest entry checked
ContactsPresent, spot-checked
Example counts, shown to make the method concrete. Matching numbers folder by folder are what a finished conversion looks like - hope is not a column in this table
1

Open the PST or Import It - Choose Deliberately

  1. Open Outlook Data File attaches the PST as a separate set of folders beside your mailbox. Nothing mixes, nothing duplicates. Choose this for archives and for verification
  2. Import pours the PST's contents into your existing folders. Choose this when the PST is the mailbox's new home - a migration or a restore
  3. When in doubt, open first. You can always import later; un-mixing an accidental import is nobody's idea of a good evening
  4. To open: File > Open & Export > Open Outlook Data File, pick the PST, and it appears in the folder pane
2

The Import Wizard and Its Duplicates Question

Importing runs through the same Import and Export wizard, choosing Import from another program or file, then the PST, then the folders to bring in. On the way it asks one question that deserves a slow answer:

  1. Replace duplicates with items imported - the PST wins wherever both sides have the same item. Right for a restore over a damaged mailbox
  2. Allow duplicates to be created - everything lands, doubles included. Almost never what you want; choose it only for a deliberate merge you will clean by hand
  3. Do not import duplicates - anything already present is skipped. The safest default for topping up a mailbox from a backup
  4. Tick Include subfolders, and choose whether the items land in a named folder or in the matching folders of your mailbox
3

Verify With Folder Counts - Five Honest Minutes

  1. In the source - the live mailbox or the exported profile - click a folder and read the item count from the status bar at the bottom of Outlook
  2. In the PST, click the same folder and read its count. They should match exactly
  3. Cover at minimum: Inbox, Sent Items, your biggest project folder, and any local-only folders you rescued
  4. Then spot-check content, not just numbers: the oldest mail, the newest mail, and one large attachment that must open
  5. Finish with calendar and contacts: scroll to your earliest appointment and search for a contact you know by heart
4

The Three Mismatches and What Each One Means

  1. PST count lower in every folder - the export ran before the sync finished. Redo it after a full download, on the working profile
  2. One folder missing entirely - it was not selected, or it lived outside the exported tree. Re-export just that folder and import it in
  3. Mail matches, calendar or contacts empty - the classic selective-export miss, especially with IMAP This computer only folders. Export those folders by name and add them
5

Only Now Retire the Source

Keep the original OST and the old profile exactly as they are for a few weeks of normal use after a verified conversion. Storage is cheap; the day you discover a missing folder three weeks later, that untouched source is the difference between a ten-minute top-up export and a permanent loss. When the PST has earned your trust - counts matched, samples opened, time passed - then clean up, and not a moment before.

🔴 Verification is part of the conversion, not an optional extra. Every horror story in this series - the empty calendar, the year of missing mail - was discoverable in these same five minutes and fixable while the source still existed. Count first, delete later, in that order, every time.

🎥 Watch the Complete Process in the Video

Watch the video end to end once more with your verified PST open beside it - every step you just checked is the process it demonstrates.

▶️ Watch Full Video
❓ Common Questions (FAQ)

The counts match but a few attachments will not open - is the PST corrupt

Not necessarily - first check whether those same attachments open in the source mailbox. If they fail there too, the damage predates your conversion and the PST faithfully copied it. If they open in the source but not the PST, redo the export of that folder after a full sync.

Should I keep the PST attached permanently

For an archive, yes - attached and read-mostly is exactly its job. For a working mailbox that now lives on a server again, the PST is your backup: close it in Outlook, store it safely, and refresh it at the next migration rather than letting it drift out of date while attached.

How long should I keep the old OST after converting

A few weeks of normal use after your counts have matched is a sane rule. The OST costs you only disk space while it sits there, and it is your only top-up source if a missed folder surfaces late.

This guide is based on the Convert OST to PST Free video by Technical Anshu • Stuck on any step, ask in the video comments and the community will help you 🙏