Hi, for some reasons outside sanity, I'm required to setup a Zimbra 7 server like this:

Internet --> GW1 (relay+antispam) --> APP1 (relay+antispam) --> Zimbra (MDA+antispam).

Is this supposed to work?, won't I get false positives easier??, any good arguments to avoid this?. I need disclaimer support so at least amavisd is required on the Zimbra side from what I remember.