I use qmail to scan my incoming and outgoing messages for virus, using qmail-scanner. I don't have local users. I use smtproutes to deliver scanned messages to another mail server. For outgoing messages, users connect directly to qmail's SMTP. Can i use maildrop to copy some user's (not all) messages to a local audit account ? And can I do this using keywords too (i.e. copy every message that contains the word sex to an local audit account) ? And the last one, copy messages with some kinds of attachments, like xls, doc, etc.

Thanks in advance.