access to impersonated cloud archive when primary mailbox is on-premises in hybrid environment

Aug 11, 2015 at 8:43 PM
We have a customer with hybrid environment with primary mailbox on-prem and archive in the cloud (o365).

Heretofore, we have been able to get a mailbox DN and server DN from EWS User Settings in order to pick up the info needed to establish a MAPI connection to an impersonated archive using the CreateStoreEntryID/OpenMsgStore mechanism.

But in this user environment, the DN values returned by EWS are both empty. The only relevant value is the smtp address of the could mailbox.

Is this expected?

Should the DN's be populated at the customer site config?

If these can be bona fide empty, how can we connect via MAPI?

Thank you very much.
Aug 25, 2015 at 12:57 PM

First, you should be using the Plain Old XML (POX) Autodiscover endpoint to gather settings to create an Outlook profile. The SOAP Autodiscover endpoint doesn't contain all the information to configure an Outlook profile properly. My guess is that the target mailbox is using the MAPI over HTTP protocol rather than the RPC over HTTP protocol and that's why the information is not available in the SOAP Autodiscover response. Here is a way you can confirm my guess:
  1. Use Outlook's Test E-Mail Autoconfiguration tool to pull back the POX autodiscover response from the server. An article describing how it can be done can be found here:

Resolve Exchange Free / Busy and Communicator Presence Issues
Specifically, the section labeled Step 3: Check Autodiscover and Exchange Web Services

If the target mailbox is indeed using MAPI / HTTP as the protocol you can either disable it on that client or you can use the Autodiscover response to configure the profile to use MAPI / HTTP.