OWA Exchange 2016 - Problems with Autodiscover from external access

Hey F5 Community!

 

At the Exchange-Server of the customers, the Login-Syntax from the Outlook-Autodiscovery, like its usually pre-configured from Microsoft, does not work.

 

The customers have an outlook.customer.com OWA Access, and also an autodiscover.customer.com URL. They login with "domain\SamAccountName" or "UserPrincipalName". The Login possibilities at the F5 should have the same Login-Syntax like OWA for AutoDiscover.

 

On the testconnectivity.microsoft.com site belongs to the SamAccountName also the intern domain, which should not be missing. Because without it will not work. At the moment the the Autodiscovery works only with the SamAccountName, without entering the local "domain\" infront of the username.

 

This leads to conflicts with other internal structures at the Outlook-Autodiscovery. I work in public services, this is the case: There are problems with Outlook-Autodiscovery for the "public utility" but with the "townhall" it works fine. Independent from the Windowsdomain, the Exchange-Server have to find the intern domain or?

 

Exchange Server is placed in the Townhall. Public Utility used the old OWA 2013 via TMG from the Townhall. Now Autodiscover does not work for Public Utility but works fine in the Townhall.

 

The Access Policy is pretty basic: Logon Page -> AD Query (with Cross Domain enabled) -> AD Auth (with Cross Domain enabled) -> SSOCredentialMapping (with custom mcget {session.logon.last.logonname}) -nothing else changed

 

Published on F5 BigIP v13.1.1 with Exchange 2016 template.