I recently changed web hosting services. All went well. I can now reach my webpage and email services without a problem anywhere but at my office. If I tried to ping the mail server it hit the wrong address. I found the old DNS entry int the server and removed it. Now it tries to ping the correct address but goes nowhere. I tried manually entering the host(A) entries adn no luck. I don't see anything in the firewall(CISCO PIX 515E) that should be preventing my network from connecting to the proper addresses. I'm stumped. The hosting change occurred last Friday.
I have this problem too.