I am encountering an annoying issue that I am hoping someone can assist me in finding a solution for. I am using Exchange 2010 SP1 and Outlook 2010 SP1. Reproduction steps are as follows: Log into Exchange 2010 server and launch the EMC. Create a new user through the integrated "New Mailbox" wizard. Log into any workstation in the domain (DNS: DOMAIN.LOCAL / NETBIOS: DOMAIN). Launch Outlook for the first time to invoke add new account wizard, choose to setup a new mail account and autodetect settings. This launches the "Online search for your server settings" window. It has a green check mark next to "Establish network connection", a greek check mark next to "Search for username@domain.com server settings" (domain.com is our public TLD, domain.local is our internal AD domain name). I then get a Windows Security prompt asking me for the password for username@domain.com (not domain.local). It will not accept the user's password in this format - I have to manually choose "Use another account" and specify DOMAIN\username and enter the password for it to complete the wizard and add the account. Does anyone have any idea why: This security window is appearing at all and it isn't using Windows Authentication to setup the account or This security window is pre-populated with the username@domain.com format vs. domain\username format or This security window won't accept the users credentials for the SMTP address associated with their AD account Any help would be greatly appreciated - as this is quite annoying. Thanks in advance!

> This security window is appearing at all and it isn't using Windows Authentication to setup the account You'd have to look at the security settings on the virtual directories. Is this happening on your Internal network or from the Internet? > This security window is pre-populated with the username@domain.com format vs. domain\username format That shouldn't matter if username@domain.com is the user's UPN. > This security window won't accept the users credentials for the SMTP address associated with their AD account The SMTP address isn't a security principal. If you want it to be, change your UPNs in your domain to match the SMTP address. Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Thank you for your reply Ed. To respond to your comments in order. This is happening to clients on the internal network, or those connected to the internal network via UAG DirectAccess (I don't have Outlook Anywhere enabled at this time). That is the issue however, username@domain.com isn't the UPN - username@domain.local is the proper UPN. I understand that the SMTP address isn't a security principal, I was just mentioning it to differentiate it from the actual UPN of the user (as I am seeing the SMTP address being autopopulated in the security window vs. the UPN or the DOMAIN\username format). Additionally it is worth noting that I am only seeing the security window when configuring Outlook with users that have been recently created and not with users that have existed for quite some time. With users that have existed for some time the security window never appears, and the "Online search for your server settings" process completes without error (even though it shows the username@domain.com value in that window and not the username@domain.local or PALADOR\username format). I am going to keep looking and see if I can find any differences between the already existing accounts (that work) and the newly created accounts (that cause the security window to come up) though I would appreciate any insight you might be able to add in the meantime. Thanks again!

You can change your UPN to be the same as the e-mail address; your users may find that convenient. I'm not claiming that's related to your issue, however. Other than that, I'm stumped.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."