I've had this issue a couple times now and the fix has just "happened" the last couple times, and I didn't put two and two together until this time.  I'm using outlook 2011 on mac to connect to my work email, which has been working great.  I also have the exchange account on my iDevices, no issues for 2-3 years.  Suddenly, after plugging into the work LAN instead of our guest wifi system, as soon as I disconnect the ethernet, i get "not connected to "valleymed".  It won't connect now, unless the LAN is plugged in.  When I'm on the LAN, everything works fine and as normal, but I cannot get it to connect, either at home or wherever.

I tried changing the password just to see if I would get a login error, nothing.  Last time this happened, even after a clean install and new database, I still couldn't get outlook to connect or detect our exchange settings.  I believe it didn't start working until I got a certificate or authentication popup suddenly a couple days/weeks later.  

Any ideas?