SSSE / PIMSI with Exchange 2010 automatically sends out emails to attendees

Hi All

I've set up SSSE (Siebel 8.1.1.6 with ACR560) with an exchange 2010 server and am currently testing appointment synchronisation from Siebel to Outlook.

Actually it works (which is absolutely great news!), but every time a Siebel appointment is created in Outlook, an email is automatically sent out to the contact person connected to this activity.

Just imagine in a production environment, all customers we create Siebel appointments with, would receive those email invitations ... this would be horrible. I am looking for a way to stop this (since SSSE 2003 did not do it).

There might be several approaches (like denying ssse-admin to "send on behalf") but I wonder if there is a clean, official approach?