Short story: Exchange box died. Rebuilt with same host name. Old mailstore is lost. All mailboxes will have to be removed and re-added.

The only backups I was able to make were the locally cached OST files. Now that the Exchange mailbox is a different ID, Outlook won't accept them as a data file, nor can I import them.

I'm sure there has to be a way to either convert these to PST reliably, or import directly, or possibly modify the SID information to load with the current mailbox.

Any suggestions?


Can you open up the old Outlook profile, export the mailbox to a PST, setup the new profile, then import that?

If not, you'll need something to convert the ost to a pst. Like this:


  • +1 first option has worked for me – Dave M Sep 29 '11 at 18:29
  • I'll give it a try... The old Outlook accounts are still active and I can log in offline mode. – derjur Sep 29 '11 at 18:31

You should have probably performed a recovery installation of Exchange. As it stands, that may not be possible anymore. If not, then you'll need a third party tool to convert (export) the ost files to pst files.

  • The recovery wouldn't run, so I manually cleaned out a few bits in AD to make room for the new server. With the mailstore gone, I figured this would be easiest. Didn't anticipate having to restore from OST. – derjur Sep 29 '11 at 19:05
  • Well good luck. I know there are a number of products on the market that claim to be able to export an ost file to a pst file. As Jason pointed out though, you may not need it. If Outlook will open with the old ost file then it should be a simple matter to export the contents of the ost file to a pst file. I used this same method with an Exchange 5.5 server many years ago. – joeqwerty Sep 29 '11 at 19:07

I've been using an app that converts OST files from the users' profiles into PST files, then manually loading the PST information into their live and current mailbox. This has been working well, although a tedious and arduous task.

The tool was bought from systoolsgroup.com. Haven't had any issues with it yet, although batch import would have been nice (we bought the personal version).

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