How to de-duplicate mail items in Outlook 2010?

We have a user who used Import, instead of 'Open Data File', to import a large number of mails from a pst file which he exported, instead of archived, years ago. As we can see, there are now many duplicate mail items in his Outlook. Is there any way to de-duplicate the mail items in Outlook?
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Naranthiran DSystem AdministratorCommented:
You can use the plugin to do this job.. search for the plugin or click the below link.

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Another one is the Outlook Duplicate Items Remover:
Will SzymkowskiSenior Solution ArchitectCommented:
There is no way natively to remove duplicate emails without going through them all manually. However, there are some 3rd party products out there that can do this. See the link below for details.

Thanks for the grade. Good luck.
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