What version of MEG are you using? I looked at version 7.6.3 and 7.5.4 in my test setup and both allow destination IP and destination host name as variables for address masquerading preset rules. Destination mail address isn't an option though. Both of my appliances are in explicit proxy.
Hi Ryan, i'm using 7.6.3.
I have spoken about destination mail address to mean destination criteria in general.
As you see in How to use protocol presets on McAfee Email Gateway and in https://kc.mcafee.com/agent/index?page=content&id=KB71202 destination IP and destination host name as variables for address masquerading preset rules are present but not used when meg is in explicit proxy mode.