Exchange 2013 CU2 on Server 2012.  Currently mixed with Exchange 2010.  Moved my test mailbox to 2013 and Outlook 2013 continually pops up asking for the password.  

Based on another thread I tried:

Get-OutlookAnywhere -Server emsrv-Exch1.emcc.edu | Set-OutlookAnywhere -ExternalClientAuthenticationMethod NTLM

But that did not help.  Manually changing the client from Anonymous to NTLM helped but I don't want to have to manually change everyone's client.  Is there a server setting I can set or maybe a GPO to deploy for the client?

Hi

Include basic authentication and do an IIS restart and your clients should stop prompting for credentials. Also make sure that IIS authentication is set to Basic,NTLM.

• Marked as answer by Steve R Tuesday, December 03, 2013 3:40 PM

Awesome!  Worked exactly as predicted.

Include basic authentication where?  and why do an IIS restart when Outlook is a MAPI client.  I didn't think it used IIS unless running Outlook over http.  Please explain to help me understand.   thanks