We have a root domain and several child domains, Exchange is hosted on one of the child domains that is only for application purposes, users are in other child domains according to the region (NA, EMEA,APAC etc) for each region we have exchange servers (remember that exchanges are on separeted domain than users), all outlook clients are configured to use HTTPS connection as internal connection (outlook anywhere internal). one of the regions decided to use outlook anywhere through internet instead using the WAN as internal connection (Exchange servers are centralized on regional datacenters so each country is connected by an MPLS link). we have deploy cas's servers, load balance and tmg for publishing. however we noticed than once external urls are configured (for internal connection was not needed, now for outlook anywhere through internet is need it) outlook clients via autodiscover, automatically started reconfiguring using the new external hostname including clients from other domain regions, we deploy a GPO to avoid external hostname change, however oab, oof and ews urls cannot be controlled by GPO. Also, we only have administration over the region, we cannot deploy the gpo to all the forest. we need to avoid outlook reconfiguration. we are a very large enterprise so the change to outlook anywhere through internet must be accomplish by phases and very control. please your suggestions. thank you Capecol MCSA - MCTS Exchange Server 2007 - 2010 - MCITP Messaging 2010 - MCT Blog: http://capecol.spaces.live.com/default.aspx

Hello, Is there any update on this thread? Thanks, Simon Wu Exchange Forum Support Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

Simon, sorry for the big delay, i just have time to deal again with this. This was not the solution i was expecting, deploying xml for 12 thousand users will not be at all easy and administrable.Capecol MCSA - MCTS Exchange Server 2007 - 2010 - MCITP Messaging 2010 - MCT Blog: http://capecol.spaces.live.com/default.aspx