XCON: Changing MTA Conformance on X.400 Connectors Fails

• Microsoft Exchange Server, version 4.0

SYMPTOMS

If the message transfer agent (MTA) conformance of a Microsoft Exchange Server X.400 connector is changed while the Microsoft Exchange MTA is running, messages will be either returned with a nondelivery report (NDR) or lost entirely.

CAUSE

When communication occurs between Microsoft Exchange sites, the X.400 connectors at both ends should be configured to use the same MTA conformance, either the 1984 or 1988 standard. If the X.400 connector on one server uses one type of MTA conformance and the other server uses another type, the encoded message transfers between servers will not be interpreted correctly. This is because the reliable transfer service element (RTSE) settings defined by the 1984 and 1988 standards are not compatible with each other.

RESOLUTION

Verify that the MTA conformance option found on the X.400 connector's advanced properties page matches what is used by the Exchange Server or other X.400 system at the other end of the connection, either 1984 or 1988. If you need to make any changes, restart all the services on both servers. This will re-encode any messages in the queue waiting to be transmitted.