Tuesday, November 06, 2012

OWA and Outlook RPC URLs

A question came up at Exchange Connections this past week about using a separate name space for the OWA/Web Services/ActiveSync URL than you use for the RPC Client Access area.   eg...
owa.domain.com   versus

Microsoft recommends keeping these separate.  While it *does* work if they both point to the same hostname and/or IP address, if they are separate, you reduce the risk of external Outlook clients (Outlook Anywhere / RPC over HTTP) timing out.  

Here is the text from TechNet:

It's important that the (FQDN) specified in the command be only resolvable internally. If the name is also resolvable externally, these external clients will attempt to connect to the array via a TCP connection instead of HTTPS.