The latest challenge we have overcome is related to having a .local internal Domain, in particular Mac clients and Exchange connectivity.  Our MacBook Users in particular had issues with getting email from Exchange via Outlook or Entourage.  The MacBook users had to edit their Account Preferences and change the URL each time they went off campus or came back on campus since the internal .local URL did not work off-site and the external URL didn’t work on site for them.  Though they were gracious enough to do this, this was definitely something we needed addressed.  After some research, we learned this was a known issue for both Exchange Server 2007 and 2010 and there wasn’t a clear cut answer in any of the forums we researched.

The answer is multiple parts since we did have the external mail server name working internally at one point.

  1. The first fix was another entry in our internal DNS that pointed another external server name (_autodisover._tcp in the external DNS name space) to the internal IP address.
  2. The second part was to launch the Exchange Server Console in the Server Configuration-> Client Access and make all of the internal server name references the same as the external (.org) server name references within each URL for OWA, Exchange ActiveSync, OAB, and Exchange Control Panel.
  3. While still inside the Exchange Server, the EWS had to have the same server name listed in the internal reference as the external server name.  This had to be done through a command in the Exchange Management Shell.  It would be similar to this, but for the internal server.
  4. After these things were done, we did the iisreset command to restart IIS (can also be done through the GUI or in Services).
Once we had these changes implemented, it partially worked, which was a puzzle.  It would work on wifi, but not on our LAN.  One of my volunteers did some sniffing and learned that even though we had an Proxy Automatic Configuration file (PAC) for our Proxy settings that told e-mail not to go through the proxy, Outlook was still choosing to go through the Proxy anyway. The entire system, except for Outlook, was using the PAC.
What we did then was manually create the PAC configuration in the Mac’s network settings. This was checking the box to “Exclude Simple Hostnames” in the  Ethernet device Proxy configuration and adding internal server IP addresses, external hostnames including the autodiscover name to the “Bypass Proxy Settings for these Hosts and Domains”.
Once we did that, Outlook now defaults to the external server name (.org) and also works internally.