Cannot create MAPI.Session on windows 2008 R2

In my application I use CDO 1.1.2 to send Mail messages from multiple Exchange account. Recently I faced the following problem. When I impersonate running thread under account that differs from application process owner and has no administrative rights I cannot create object MAPI.Session. Calling

CComPtr<MAPI::_Session> pMAPISession;

rc = pMAPISession.CoCreateInstance(OLESTR("MAPI.Session"));

gives rc is equal -2147221234 (0x8004010E). On the other hand if account being impersonated has admin rights object is created, but application fails. This feature takes place on operation system Windows Server 2008 R2. On windows XP all work well. How can I fix this issue?

Alexander