Hi, I have 3 different sites geographically dispersed, California, DC and NY, all 3 sites are part of of the same domain, acme.org I have 2 E2k10 CAS servers at each site, and i'm trying to configure the autodiscover in the best possible way. Array1 would be setup as CAcas.acme.org array2 would be setup as DCcas.acme.org array3 would be setup as NYcas.acme.org We have 2 mailbox servers at each site that would be serving emails to the respective users at each site. In order for me to set the Autodiscover URL, should i set the same autodiscover in all 3 sites as autodiscover.acme.org ? or should i set a different Autodiscover for each site for example autodiscover.CA.acme.org, autodiscover.DC.acme.org and autodiscover.NY.acme.org We don't have an external OWA presence, access to OWA is performed using RSA Securid ID and Juniper, so i don't need to configure extermal URL's for the CAS services. Internal users though, would use OWA depending on the site they're located, so a mailbox located in NY would use NYcas.acme.org as their default OWA server, and get proxied to the NY cas array if they connect to a different proxy array at a different site. same thing for the Outlook Client.

Another possibility to manage where AutoDiscover requests are served instead of creating Site specific URLs is to make use of AutoDiscoverSiteScope - Configure the Autodiscover Service to Use Site AffinityJesper Bernle | Blog: http://xchangeserver.wordpress.com

If you manage a large, distributed organization that has Active Directory sites that are separated by low-bandwidth network connectivity, Microsoft recommend's that you use site affinity for the Autodiscover service for intranet-based traffic. To use site affinity, you specify which Active Directory sites are preferred for clients to connect to a particular Autodiscover service instance. Specifying which Active Directory sites are preferred is also known as configuring site scope. http://technet.microsoft.com/en-us/library/aa997633(EXCHG.140).aspxThanks Mhussain

Here's a link to the autodiscover whitepaper, it will give you a lot of details http://technet.microsoft.com/en-us/library/bb332063%28EXCHG.80%29.aspx Jonas Andersson | Microsoft Community Contributor Award 2011 | MCITP: EMA 2007/2010 | Blog: http://www.testlabs.se/blog | Follow me on twitter: jonand82

Hi, I recommend you using the different Autodiscover URL for each site which can provide the high availability for the Outlook clients. Thanks AllenAllen Song