Fresh Exchange 2010 SP1 install with the 5 additional patches specified, nice that there was an error during the install regarding mailbox access role. Anyways, regardless of that. I have split-DNS setup replicating the public DNS zone records on the internal AD/DNS servers. A UCC SSL certificate from GoDaddy with subject alternative names of exchange.domain.com (user will use this for OWA and Outlook Anywhere) and autodiscover.domain.com using cert request from the new cert request wizard in the Exchange 2010 management console with I,P,M,S set to that cert. Public DNS records for exchange.domain.com and autodiscover.domain.com are created on the outside pointing to external IP, plus both are created inside pointing to internal IP. Autodiscover service connection point is pointing to https://exchange.domain.com/autodiscover/autodiscover.xml. EWS config has both internal and external URLs pointing to https://exchange.domain.com/EWS/exchange.asmx. I can open and set out of office info via Outlook Web App, but not Outlook via either RPC or RPC over HTTP. This is NOT THE FIRST TIME I'm setting up Autodiscover having going through the agony with Exchange 2007, I'm using the exact same setup but this is somehow not working on Exchange 2010. I have tried resetting (delete then recreate) the EWS IIS virtual directory and reinstalling CAS role and none of those are working. Autodiscover succeeds using the autodiscover test from Outlook 2007 and I can pull up the exchange.asmx page after authenticating using a domain account with mailbox on the Exchange server. Same result on Outlook 2010, so it's not the client. I'll have to resort to Exchange 2007 SP3 if 2010 sp1 keeps sucking this way. any advice is appreciated. thanks

So, currently you have tried the following steps: · Reset /EWS virtual directory · Reinstall CAS role · Retrieve AutoDiscover response via “Test E-mail AutoConfiguration” in outlook client · Successfully browse EWS URL · Confirm that the issue happens to all outlook clients (2007, 2010) via either RPC or RPC over HTTP Could you provide the error information when you failed to open the OOF option in outlook? Is there any related error or warning event in the application log on the CAS server after reproduced the issue? Is there any related trace in the IIS log on the CAS server after reproduced the issue? Please use the following steps for troubleshooting: Please enable the troubleshooting logging on the outlook clients, reproduce the issue, and then check the log files that end with “oof” in the %Temp% folder Please increase the diagnostic logging level on following categories for MBX and CAS servers, reproduce the issue, and then see if there’s any related event in the application log on the MBX and CAS servers · MSexchangeMailboxAssistants\Service (MBX) · MSexchangeMailboxAssistants\OOF Assistant (MBX) · MSexchangeMailboxAssistants\OOF Library (MBX) · MSExchange Web Services\Core (CAS) Please run the cmdlet below on the problematic users · Test-OutlookWebServices · Test-WebServicesConnectivity Please run ExBPA against the exchange servers for health check James Luo TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.