MM 5.2 with MAS and MSS and latest ROC I can find installed in outlook 2010. I am tracing it in my pc. The only time it check for messages in when outlook is started. After that it doesn't matter if I click send/receive all groups or wait for the timer, I never see it even try to talk to the MM system. When I close outlook I see it send resets on the tcp connections that it had. When I restart outlook it checks with the MM system and downloads any messages.