Outlook ANywhere the best would be to configure OL clients with Basic Authentication. However i would like to divert your attention to below article just in case if you have missed anything while configuring Outlook Anywhere http://www.exchange-genie.com/2008/02/configuring-outlook-anywhere-for-exchange-2007-sp1/ Vinod |CCNA|MCSE 2003 +Messaging|MCTS|ITIL V3|

hi,just look at here ;http://technet.microsoft.com/en-us/library/cc179036.aspxand also this article;http://technet.microsoft.com/en-us/library/cc179036.aspxregards,Mumin CICEK | Exchange - MVP | www.cozumpark.com | www.mumincicek.com

Hi,Please check whether this issue still occurs when changing the NTLM Authentication to Basic Authentication. It seems that this is the known issue which matches with the description as below link:http://technet.microsoft.com/en-us/library/bb123889.aspxAdditionally, a good online testing tool which you can try do a check:https://www.testexchangeconnectivity.com/ThanksAllen