Event ID - 125

Event Id125
SourceMSExchangeMTA
DescriptionA fatal error occurred reading a value from the directory. No MTA name was found. Contact Microsoft Technical Support. [<value> <value> <value> <value>] (16)
Event InformationCheck the Local MTA name on the OverRide Tab of the X.400 Connector Properties dialog box. Use Network Monitor to capture Network Traces, then view these traces from Network Monitor for any network issue. Stop and restart the directory service on the sit.

Refer the Microsoft article given below for more information about this event.
Reference LinksXADM: The Information Store and MTA Services May Not Start After You Apply SP2

XADM: Exchange 2000 Error Messages Are Generated Because of SeSecurityPrivilege Right and Policytest Issues

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