I am working on a SBS2k3 server with exchange 2003. My mail system is working for the most part however I am receiving NDR's with the error code of 5.3.0 . I know that this means that it is a permanent delivery problem where its to "other or undefined mail system". I have set up message tracking which tells me that the mail gets to "started outbound transfer of message" then delivers the NDR. Further more I hace logged onto dnsstuff.com and verified that the domain exists together with sending a mail from another site with the same op sys and exchange where it gets delivered.
Also I have downloaded winroute and repaired any suggestions which it suggested which wasnt much, where now it says that wmi is working correctly.
I am unsure what to try now from here on....does anyone have a suggestion that I could try from here on.