We are looking at migrating our mail service to Zimbra. Currently, we have a cluster of servers that does virus and spam filtering. The suspect-spam messages are tagged with a X-header and delivered to the SMTP host. The SMTP host then uses procmail to drop the messages either into INBOX or a Quarantine mailbox.

Could I configure Zimbra to do this kind of delivery based on the X-header or is there a better way to do this with Zimbra?

Thanks in advance.