Ok, this is an interesting situation. 2 months ago I migrated all my users to Exchange 2013 and the whole thing worked great. I had 2 servers setup and everyone seemed to be connecting to the main one (which was what I had planned). I had the second one as a backup and so I connected all the databases together in a DAG. Synchronizations were going good and everyone was connecting and happy, even the boss was connecting from home with zero issues.
Here is where it got interesting.
I was asked to add a third server, offsite. I did that and added it to the DAG over VPN and it also is working like a charm (as far as synchronizing). But where it gets interesting is here. Now it seems many of the users are connecting to this one (new offsite server) in their Outlook (more settings area) and not the local server in their office. The databases that are active are all on the Exchange server that is in the office, so that makes it very transparent to the users (as far as latency) but when you go into the Exchange Proxy settings and look at the Connection Settings URL it is giving some users the offsite Exchange Server and some users one of the Internal servers.
Now, my end game is to have a load balancer that would direct everyone where to go in a more reliable way but for now is there something I can do to make the user go to the server I want them to go to? I want the server that has the active databases to be the one that everyone connects to. I am guessing that to do that will require a load balancer, but if not please let me know. If I do need a load balancer (not for Load balancing but for CAS availability) which one do you recommend?