Programmatically connecting to another mailbox when MAPI / HTTP is used

I’ve been meaning to create this post for a while, but haven’t got around to it. I had a case recently where a customer wanted to connect to a user’s Archive mailbox for which the service application had permissions.  However, the transport in use was MAPI over HTTP (MAPI/HTTP).  He was getting the error MAPI_E_CALL_FAILED (0x80004005)…

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