Hi, I upgraded Exchange Server 2013 to CU1 today and found a new virtual directory named 'mapi' under the IIS Default web site on the CAFE role and the Exchange Backend web site on the Mailbox role, along with their corresponding app pools. Out of curiosity I downloaded MFCMAPI 15.0.0 and ran it against that Exchange server. It works fine, but it did not cause an instance of w3wp to start for the mapi app pool on either role. MFCMAPI seems to be using the RpcProxy app pool instead. I know that the MAPICDO upgrade was just released but haven't installed it yet because I don't have any applications that use CDO at the moment. What is the purpose of the new mapi virtual directories and app pools, how do they work and what uses them? Are they internal only, or are they connected to the MAPICDO upgrade? If I stop or remove them, what breaks? Thanks, John Lowery

http://blogs.technet.com/b/exchange/archive/2013/01/25/exchange-2013-client-access-server-role.aspx Third-Party MAPI Products I am sure that a few of you are wondering what this change means for third-party MAPI products. The answer is relatively simple these third-party solutions will need to leverage RPC/HTTP to connect to CAS2013. This will be accomplished via a new MAPI/CDO download that that has been updated to include support for RPC/HTTP connectivity. It will be released in the first quarter of calendar year 2013. To leverage this updated functionality, the third-party vendor will either have to programmatically edit the dynamic MAPI profile or set registry key values to enable RPC/HTTP support. I do also want to stress one key item with respect to third-party <acronym style="border-bottom-width:1px;border-bottom-style:dotted;border-bottom-color:black;cursor:help;" title="Messaging Application Programming Interface">MAPI</acronym> support. Exchange 2013 is the last release that will support a MAPI/CDO custom solution. In the future, third-party products (and custom in-house developed solutions) will need to move to Exchange Web Services (EWS) to access Exchange data.

Thank you for the prompt and useful reply. John