XCON: NDR "Invalid Parameters"

When a message originates from a third-party message transfer agent (MTA) by way of an X.400 connection to the Microsoft Exchange MTA with an administrative management domain (ADMD) that is a space, a non-delivery report (NDR) is generated with the message text "invalid parameters."

This happens because the MTA improperly handles a numeric ADMD. Many third-party MTAs generate a numeric character 0 for a space rather then an alphanumeric null. Microsoft Exchange Server properly supports this in all O/R address fields but not in other parts of the message envelope (for example, MTSID, Bilateral-Info, External and Internal-Trace-Info).

The Microsoft Exchange Server 4.0 MTA does not properly handle the numeric ADMDs; however, the Microsoft Exchange Server 5.0 MTA is able to properly distinguish between numeric and alphanumeric ADMD fields.

To work around this issue, do one of the following:

• Change the third-party ADMD to something other than a space.
  
  -Or-
• Upgrade to Microsoft Exchange Server 5.0.

Microsoft has confirmed this to be a problem in Microsoft Exchange version 4.0. This problem has been corrected in the latest U.S. Service Pack for Microsoft Exchange Server version 4.0. For information on obtaining the Service Pack, query on the following word in the Microsoft Knowledge Base (without the spaces):