I am experiencing some issues on my exchange 2007 environment running on win 2008 SP2 . When users try to define a new outlook profile they are prompted for passwords over and over and on the exchange event log i can see (The program w3wp.exe, with the assigned process ID 4148, could not authenticate locally by using the target name HTTP/Mail.contoso.com. The target name used is not valid. A target name should refer to one of the local computer names, for example, the DNS host name.)ammarhasayen

What version of Outlook and how are they connecting? Please verify if OL2007, http://www.msexchange.org/articles_tutorials/exchange-server-2007/management-administration/configuring-outlook-2007-exchange-server-2007.html MVP Exchange Server

Are you using Outlook Anywhere?Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog