[PERDITION-USERS] Perdition + imap (maildrop doesn't send bounce back messages.

Dear All, I am using perdition + courier + postfix+ ldap+ maildir (mail quota) on my mail servers. All the functions are working fine on the server except one small issue. I configured mail quota on the mail servers, suppose if the user quota becomes full condition 1 if the sender mailbox and receiver mailbox existing on the same mail server the sender get a bounce back message that user quota is full. if the sender and receiver mailbox existing on two different machines , it doesn't bounce back any messages.bcoz the receiver home directory is not existing on the same server ERROR LOG relay=maildrop, delay=0, status=deferred (temporary failure. Command output: /usr/local/bin/maildrop: Unable to change to home directory. I am looking for a breakthrough to tackle this issue Any ideas and suggestions are welcome Best regards Paul