When you set the troubleshooting logging level on the Exchange 2000 Server message categorizer to
Maximum, when you receive inbound Internet mail, an event similar to the following may be logged in Microsoft Event Viewer:
Event Type: Error
Event Source: MSExchangeTransport
Event Category: Categorizer
Event ID: 9004
Description:
Categorizer encountered a hard error while processing a message. While processing user 'smtp:sender@sendingcompany.com', the function 'CPhatCat::HrSetInboundCharsetHint' called 'HrGetDomainInfo' which returned error code '0x8007054b' (The specified domain either does not exist or could not be contacted.) A DSN has been generated.