Our company is running a zimbra server in test mode as a gateway mail server in front of an exchange server. Our goal is to test zimbra in order to migrate all accounts from exchange to zimbra.

For the time being, the zimbra server is only filtering spam messages and relaying incoming emails to the exchange server.

Now I would like to set advanced filter using procmail. In fact, I basically want to forward all emails with X-Spam-Flag=YES to a special account on the exchange server.
I did found some good "how to" about procmail, but I don't know how to set it up inside a zimbra server.
Where should i create the .procmailrc file.
How do I automatically start the procmail daemon. Will it works "out of the box" with zimbra ?
Thanks for your help