In my company, a government organization we have decided blacklisted free email likewise hotmail, yahoo, latinmail, mixmail and others but only is accepted when is whitelisted by means autowhitelist (obviusly, when our user send a email to these free emails). In this moment we are migrating our exchange server to zimbra but I have this problem.
In my exchange server we have a GFI antispam where all messages of sender blacklisted is forwarded to email administrator, how can I to do this in Zimbra?

Regards.

Felix