Outlook Prompts For Credentials

Written by Allen White on February 14, 2011. Posted in Exchange 2007, Exchange 2010, Microsoft Office, Microsoft Outlook

IT Problem

When you run your outlook client you are prompted for authentication again, with the standard authentication box as seen below. This can happen in outook 2003, outlook 2007 and outlook 2010.

outlook prompting for credentials

IT Solution

This is a quite a common issue and there are a few solutions and ive seen it on a number of IT forums with numerous solutions. Try the solutions below.

1.) First of all this is a known issue with exchange 2007 pre service pack 2. If you do not have the latest service pack and latest updates installed do this before going any further. Here is a link to service pack 3 for exchange 2007

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=1687160b-634a-43cb-a65a-f355cff0afa6&displaylang=en

2.) We next to make sure that windows authentication is enabled. So under server manager > Roles > IIS we need to make sure that windows authentication is selected aswell as basic authentication.

integrated authentication

Additional to this, In IIS under the virtual directory, Autodiscover properties> Directory Security> Authentication Methods> make sure “Integrated Windows Authentication” is selected.

3) Finally under the below virtual directories. Select them all.

AutoDiscover
RPC
EWS
OAB

Once highlighted select Authentication, right click on Windows Authentication and select Advanced Settings and put a check in the enable kernel-mode authentication.

If anyone is aware of further possible fixes then please comment below.

Tags: Authentication

Allen White

Allen is an IT Consultant and holds the following accreditations. MCSA, MCSE, MCTS, MCITP, CCA, CCSP, VCP 4,5, 6 and HP ASE, AIS - Network Infrastructure.