Email and UPN do not belong to the same namespace

Hi There,

Just recently I helped out in a case where hybrid Exchange users with the mailbox in the cloud were failing to retrieve autodiscover configuration data.

It was an environment with multiple federated domains, and mailboxes split between on-premises and O365. On-premises mailboxes worked well, only O365 mailboxes were failing, and, more bizarrely, one of the domains worked while the others didn't.

As we know, mail clients for onboarded hybrid mailboxes go through a double autodiscover process:

1. The first iteration discovers the on-premises mail user, which then redirects the client to the cloud mailbox.
2. The client then goes through a second autodiscover process, this time against the cloud mailbox.

Looking at the Microsoft Remote Connectivity Analyzer output, I noticed that the first iteration succeeded. The issue was with the second pass. The error:

X-AutoDiscovery-Error: LiveIdBasicAuth:LiveServerUnreachable:<X-forwarded-for:40.85.91.8><ADFS-Business-105ms><RST2-Business-654ms-871ms-0ms-ppserver=PPV: 30 H: CO1IDOALGN268 V: 0-puid=>LiveIdSTS logon failure '<S:Fault xmlns:S="http://www.w3.org/2003/05/soap-envelope"><S:Code><S:Value>S:Sender</S:Value><S:Subcode><S:Value>wst:InvalidRequest</S:Value></S:Subcode></S:Code><S:Reason><S:Text xml:lang="en-US">Invalid Request</S:Text></S:Reason><S:Detail><psf:error xmlns:psf="http://schemas.microsoft.com/Passport/SoapServices/SOAPFault"><psf:value>0x800488fc</psf:value><psf:internalerror><psf:code>0x8004786c</psf:code><psf:text>Email and UPN do not belong to the same namespace.%0d%0a</psf:text></psf:internalerror></psf:error></S:Detail></S:Fault>'<FEDERATED><UserType:Federated>Logon failed "User@domain.tld".;

Needless to say, I checked on-premises and cloud user and mailbox properties, UPNs, addresses, connector address spaces, proxy addresses, the lot, to no avail. It was all configured correctly.

Then I checked ADFS. There I found a couple of errors, so I turned on debug trace. Nothing obvious there either, so I turned it off.

I tested ADFS logon via https://sts.domain.tld/adfs/ls/IdpInitiatedSignon.aspx: Successful.

ADFS was working well per se. Somehow, it was getting incorrect details from O365.

I also suspected that somehow the ADFS proxy was breaking the SSL stream - I dealt with a similar situation before. However this idea has been dropped when the original (3rd party) proxy was replaced with Microsoft's native Web Application Proxy and the issue remained.

To recap:

• Users had matching e-mail and UPN
• ADFS itself was working
• Multiple federated domains
• ADFS Proxy (WAP) ruled out

Then I decided to re-federate the domains. Since I had very little (a.k.a. none whatsoever) information on how it was set up initially, and no details on any deployment history, tabula rasa seemed in order.

So I converted the domains to Managed, then re-federated them. Since there are multiple federated domains, I used the Convert-MsolDomainToFederated cmdlet with the SupportMultipleDomain switch.

Coffee time, to allow some time to pass to do its things (it's a distributed environment and things don't happen instantly).

<suspense>Then came the test</suspense> ...  Lo and behold: everything started to work! Every federated domain, every service.

In summary: The hybrid environment and user accounts were configured correctly, yet the wrong details were passed by O365 to ADFS. Either the trusts were incorrectly configured, or the federation metadata got corrupted. Whatever it was, re-federating the domains fixed it.