Issues with Rules when using exchange.asmx

I am using rules on my exchange boxes with scope to cover more than one box. The issue is that when I set a rule to happen after a message is sent, and the message is not sent from eM but from inside the box directly, it doesn’t process the rule. Is there a way around this? As I need the rule to process once a message is sent from the exchange box, even if the message it not sent from eM client directly.