451 4.4.0 DNS query failed on one domain



    I am getting a "451 4.4.0 DNS query failed" on one domain.


    Things I have tried:


    nslookup with type=mx. This returns 4 mx records with values of 0,5,10,20,30

    telnet to port 25 for each record succesfully

    set internal and external DNS to "all available NICs"

    changed forwarding on DNS to public DNS servers as well as the ones listed by my ISP

    Turned on protocol logging for send Connector



    Exchange 2007 RTM (current Rollups)

    Microsoft Windows Server 2003 R2 Standard x64



    Thanks in advance.

    Tuesday, March 25, 2008 11:19 PM

All replies

  • Are you still having this issue?  Did recycling the services do anything?


    Wednesday, September 24, 2008 2:44 AM