[ClearCase_guy]

Whitelisting basically involves someone specifying acceptable addresses, like so:

VicePresident@governmentcomputer
SecDefense@governmentcomputer
SenateLeader@governmentcomputer
Hillary@nogovernmentcomputerknowntomanjustaprivateserverinabathroom
HouseLeader@governmentcomputer
SecTreasury@governmentcomputer

[randita]

Love it! Obama’s a liar, but we all knew that.

[rolling_stone]

statesecretsforsale @flybynightprivate.evidence.hiding server

[mrsmith]

Right!
And her address would have to be deliberately hidden, if it was.