I am using the Exchange Managed API in combination with Exchange 2010 SP1.
I can successfully register for streaming notifications on several mailboxes using Impersonation.
When I get a notification of an appointment being created / modified, I can retrieve the appointment from Exchange.
Now I would like to know who the owner of the appointment is. That is not always the organizer.
Do you know a property on that appointment that indicates the emailaddress of the mailbox the item belongs to?
I fixed this by keeping the combination of the mailbox we impersonated to with the subscription.
In that way when we get an event, I can find the correct mailbox.