I am working on an issue with Outlook Anywhere in Exchange 2013 where external and also internal users cannot connect. This is a new server co-existing with an Exchange 2010 server that will soon be decommissioned.

When I run an Outlook Connectivity test on testexchangeconnectivity.com I get the following error. I am not seeing anything in the application or system logs. I already applied CU 8 and am seeing the same results. External is a TMG and publishing to CAS 2013 server, which then proxy to CAS 2010

Testexchangeconnectivity.com
Attempting to ping RPC proxy <external Exchange URL>.
RPC Proxy can't be pinged.

Additional Details

An unexpected network-level exception was encountered. Exception details:
Message: The remote server returned an error: (500) Internal Server Error.
Type: Microsoft.Exchange.Tools.ExRca.Extensions.MapiTransportException
Stack trace:
at Microsoft.Exchange.Tools.ExRca.Extensions.MapiRpcTestClient.PingProtocolProxy(String endpointIdentifier)
at Microsoft.Exchange.Tools.ExRca.Tests.MapiPingProxyTest.PerformTestReally()
Exception details:
Message: The remote server returned an error: (500) Internal Server Error.
Type: System.Net.WebException
Stack trace:
at System.Net.HttpWebRequest.GetResponse()
at RpcPingLib.RpcPing.PingProxy(String internalServerFqdn, String endpoint)
at Microsoft.Exchange.Tools.ExRca.Extensions.MapiRpcTestClient.PingProtocolProxy(String endpointIdentifier)
Elapsed Time: 290 ms.

Outlook internal

When i autoconfigure outlook all is setup OK and client and Outlook works. Do i enable the use HTTPS on fast network. Close Outlook and start again i get a login prompt where i not can login does not accept credentials as in OWA i can login with these credentials. Do i change in the HOSTS file autodisover and webmail back to CAS 2010 it also works

SetupServer Internal Hostname External Hostname Auth.(Int.) Auth. (Ext.) Auth. IIS Last modified on: 
2010-EXC01  webmail.contoso.com Ntlm Ntlm Ntlm 11/04/2013 10:34:55 
2010-EXC02  webmail.contoso.com Ntlm Ntlm Ntlm 11/04/2013 10:34:55 
2013-EXC13 webmail.contoso.com webmail.contoso.com Ntlm Ntlm Basic Ntlm Negotiate 04/13/2015 17:40:09 
2013-EXC14 webmail.contoso.com webmail.contoso.com Ntlm Ntlm Basic Ntlm Negotiate 04/13/2015 17:40:32 

• Edited by dirkverhagen123 Wednesday, June 03, 2015 10:46 PM
• Moved by Jason Johnston [MSFT]Microsoft employee Thursday, June 04, 2015 2:24 PM Not a development question.

Hi Sathish,

I did an iisreset on 2010 CAS and 2013 CAS no success

Also rebooted the CAS 2013 no succes.

reinstall RPC proxy on 2013 can't be done as i'm aware of.