I'm at my wits end with this issue, I desperately need some help.I have Windows Server Standard 2008 (domain controller), running Exchange 2007 for about 30 users. All patches and service packs are applied. Client workstations are running Vista Business (32bit/64bit mix) with Office Small Business 2007. All usershave roaming profiles.In Outlook, one of my users is continually prompted to authenticate with (what appears to be) a Basic Authentication prompt. If she enters her correct credentials, the prompt disappears untilOutlook is restarted, then reappears when Outlook is reopened. If she simply closes the password prompt, the message "Need Password" appears in the lower right corner of Outlook and the prompt periodically reappears on its own. No other users have this problem.I've lost track of all the steps I've taken to try to resolve this, but...She only has one mail account configured in Outlook (the Exchange account). She is not using RPC over HTTP, the server is on the LAN. I have tried changing Outlook's "Logon Network Security" option to each option with no success. "Always prompt for logon credentials" is unchecked. Connection state is "Online with Microsoft Exchange". I have compared her Outlook settings to those of other users who don't have this problem -- I can't see any differences.When I use Outlook's "Test email autoconfiguration" option WITHOUT entering her credentials in the prompt, I get this: Attempting URL https://mail.example.com/Autodiscover/Autodiscover.xml found through SCP Autodiscover to https://mail.example.com/Autodiscover/Autodiscover.xml starting Autodiscover to https://mail.example.com/Autodiscover/Autodiscover.xml FAILED (0x80040413)(As far as I can tell, the remaining errorsare becauseI haven't created DNS names for the autodiscover site.) In the IIS logs, I see a 401 error occurred.When I repeat the test AFTER entering her credentials, the test succeeds.She can read and send email whether her credentials have been entered or not. I can't figure out what (if anything) this password prompt is protecting, but it continually pops up until she fills it in.On the server, I have compared her Active Directory account and Exchange mailbox settings to other users -- again, no visible differences. I have tried logging into other workstations, some where she is a local administrator, others where she is not -- no change. I have added her account to the Domain Administrators group -- no change. I have rebooted workstations and even the server multiple times. I have restarted IIS many times.I've followed a lot of advice from blogs, forums and knowledge base articles about the above error (0x80040413) but none of them have helped, probably because they all assume every user is getting that error, not just one.Any ideas? As I said, I'm at my wits end. I'm considering movingto another state and changing my name, just to get away from this issue.-- Sam Yewell

Hi, I'm not sure if it will help you... but I remember I get identical problem with some users in my organization... but my configuration is quite more complex... because my laptop is connected on a domain and my exchange organization is on another domain... For my part, I just add a host file indicating my CAS server IP address (autodiscover)... and it resolved my problem. And also you should try to create a SRV record for ur autodiscover site.

I'll try that, but I doubt name resolution is the issue. When I log into the same workstation with a different username, Outlook works fine. When I log into other workstations with this user's account, it still won't work. I'm pretty sure the problem is something in this user's account. I just can't find it.