A useful rubric to keep in mind is: * There's no such thing as outbound mail, all mail comes in, and then it goes out...Any notion of incoming or outgoing is a mental model you overlay on your use of the Postfix MTA, the actual MTA is just a message switch. The expansion of virtual aliases happens for all recipient addresses that transit the switch. If you want different processing for inbound and outbound mail, use separate Postfix instances configured appropriately to the task at hand.
Got it, thanks for the explanation.
