mails problem dovecot
i'm facing a problem on my mail server. I'd one mail server which was running on postfix+dovecot. due to some problem I reinstalled the server with all the services after taking backup. now when it is working i want to restore the mails of all the users. problem is if i restore all the mails to respective mailboxes all the users will get all the old mails too which they have already downloaded. now i want users to download only new mails and the mails which were never downloaded after restoring the old data. is it possible? I tried by deleting dovecot.index and dovecot.index.cache files from one mailbox on test basis. it works but dovecot rebuilts the index files and allows to download all the mails which i put after deleting the index files. so is it possible to merge dovecot.index and dovecot.index.cache files any ways?????