Setting up Exchange over HTTP\OutlookAnywhere. Exchange 2003 with Front and BackEnd servers. Backend mailbox server not normally available "on the outside", so we setup NAT on the firewall for backend Exchange server xxx-mbx-01.domain.edu on HTTPS only . Initial OutlookAnywhere setup using the Exchange server name xxx-mbx-01.domain.edu works great.
PROBLEM: Older XP clients coming in VPN don't have OutlookAnywhere capabilities. Some OutlookXP clients picked up the external NAT of Exchange server, couldn't get their mail because it was only allowing HTTPS traffic in. Rolled back firewall changes so they could work. (Yes, we're working on the upgrades. Slowly)
SO ... attempted to create alias name for OutlookAnywhere users to get to Exchange mailbox server, like OAmail.domain.edu. Setup OAmail.domain.edu in DNS externaly and internally, with NAT on firewall to internal backend Exchange server. Now OutlookAnywhere clients are prompted for username & password during account setup, but do not connect to server. Error message, "Outlook could not log on. Check to make sure you are connect to the network and are using the proper server and mailbox name. The connect to the Microsoft Exchange server is unavailable. Outlook must be online or connected to complete this action." Does the Exchange Server Name have to be exact, or can aliases be used? I can ping oamail.domain.edu from external client, if that's any help.