Currently we have a URL for internal OWA access which is in the format http://webmail.domain.com. However, we never modified the internal URL listed on the CAS servers which is in the format https://servername.internaldomain.com. We would like to replace the internal URL on the CAS servers with the one that clients are actually using above. I would like to know if that causes any impact to the clients that are using OWA, etc. The reason that we would like to do this is that since we have started rolling out Outlook 2010, clients are noticing that the URL listed for Web Access in Outlook 2010 is not the same as the one they have been told to use. Thanks, RJ

if you mean to have the same internal and external url then you will need to use split dns.

No issues with programming the internalurl the same as the externalurl. This is actually the preferred method so that you do not get user confusion like you are describing. As VMinstrator says, you will need to have split DNS implemented.Tim Harrington - Catapult Systems - http://HowDoUC.blogspot.com

No, I mean that I want to change the internal URL on the Exchange server to match what the users are actually using inside. We have a separate external URL. We currently have the internal URL on an F5 to give us load balancing. The F5 redirects to the CAS servers.

Hi, You can change the internal URL. No impact to the clients. The "Internal URL" and "External URL" is used for Proxying and Redirection for Outlook Web App. More information about OWA Proxying and Redirection, please read the following article. It will be helpful for you. http://technet.microsoft.com/en-us/library/bb310763.aspx Gen Lin TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread. Thanks Gen Lin-MSFT