If I were to configure a Zimbra server per Deployment Scenario B in the Split Domain wiki entry (Split Domain - ZimbraWiki) with Zimbra accepting mail from the Internet and relaying all mail to a separate internal mail server, would Zimbra perform virus/spam scanning before relaying? Or would it simply relay with no virus/spam scanning?

The sentence in the wiki that reads "Since Zimbra can perform inbound email prescreening..." makes it sound like it would perform virus/spam scanning, but I just wanted to confirm that and see if anybody had experience with it.