again I have a problem after I had to reinstall Zimbra after an update crash...

I had a backup of my mails and synced them now with the new/clean Zimbra-Installation - but the date it shows in folder-listing is the date I copied them back - not the date I really received the mail (like it is shown in detailed email-view)
Is there a possibility to automatically update this date in the database?! Maybe someone of you has a script for doing this??