Ok i understand that you main problem is duplicat emails
so try this

Export data from Outlook
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Opened outlook.
File - Import and export - Export to a file - Personal folder file -
Choose personal folder(checked inculde subfolder) - choose a location to
save and save it.

delete the all mails from your outlook

then try this

Here is the process of importing data in outlook
Open outlook
Click on fileclick on import export
Choose import from another program or file click next
Choose personal folder file(.pst)click next
Choose under options choose do not import duplicates

and you will be free from all duplicates