We have Exchange 2013 installed in a resource forest, the user forest is where all the laptops are connected to, for some reason there's literally a non stop prompt a thon constantly going on, Ive tried mixes of security settings example using just basic or integrated but still we get prompts.
We have two CAS Servers, one I'm using to get BES connected as bes will only connect forcing NTLM as the authentication methods, then I have another MAIL which is set to negotiate, all my links point to MAIL but I think somehow the CAS server is flipping the authentication method from NEG to NTLM