postfix/courier troubleshooting - mails going into wrong folder, too many duplicates

hello, my current admin screwed up. he was configuring a working THE HORDE installation and in the process made some unnecessary changes. yesterday i ran into error "chdir maildir failed" that he fixed within minutes. unfortunatelly he did something wrong and the mails were going into a different folder (thunderbird client was displaying there were no noew mails...) now he did some changes and i have 8000 duplicates of yesterday's mails. i need someone to fix this. you need expertise with POSTIX and COURIER you'll need to start working on this right away.