I have a SBS 2012 server. Exchange 2010 had been working well. Recently we changed isp's. In doing so, I am using the provided "Actiontec" router/modem as the primary firewall. Obviously we got a new Public ip. I've made the necessary changes within the domain. The problem is none of the outlook clients will connect to the exchange server any longer (within the LAN). I've port forwarded all the necessary ports although I don't believe that would prevent outlook from connecting to the exchange server. I have several different versions of outlook running. None of them will communicate with the exchange server. All worked well with the previous isp and thier modem/router. Any suggestions would be greatly appreciated. Thank you.