Event ID - 20031

Event Id20031
SourceSmtpEvt
Description" An unknown SMTP command "
Event InformationAfter you apply Internet Security and Acceleration (ISA) Server Service Pack 1 (SP1), you may receive the above event and also it may log 20033.
CAUSE :
After the ISA Server SMTP filter is updated by ISA Server 2000 SP1, event ID 17220 and 17240 are changed to 20031 and 20033. Because of this, you cannot correctly view the 17220 and 17240 events in the Application Log after you apply ISA Server 2000 SP1. Instead, you receive a "The description for Event ID (x) in Source (Y) cannot be found" message.
Reference Links SMTPEVT 20031 or 20033 Entries in the Application Log After You Apply ISA Server SP1

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