I recently changed the Webmail MTA to be an external MTA and bypass Postfix so that I could handle split domains, and I noticed that in doing so, Zimbra has lost the ability to masquerade via the zimbraMailCatchAllCanonicalAddress feature. I'm assuming that this is because the address rewrite was being handled in Postfix. Does anybody have a moderately authoritative list of all the features that will stop working without using Postfix as the first hop off of Zimbra?