Help. I have a server with the NETBIOS and TCP/IP Host name of nature_dc. It's directory name is nature-dc. When talking to some email servers it will return the following error: HELO nature_dc.naturedc.com 501 syntactically invalid HELO argument(s) Can I just change the NETBIOS and/or the TCP/IP host name to solve this problem? Will I need to make any other changes to get this to work cleanly? (client's..DNS...etc...) Thanks for your help in this matter.