I created a OnCategoriz event sink in C#, which implemented the interface
'IMailTransportCategorize', and also I bound the event with the sink

cscript smtpreg /add 1 OnCategorize Categorizer CategorizerSink ""

I can see the registered event sink by 'smtpreg /enum':

---------
| Binding |
---------
Event: SMTP Transport OnCategorize
ID: {72046880-EFFE-4769-929B-84FAE0E24EB2}

Name: Categorizer
SinkClass: CategorizerSink
Enabled: True
SourceProperties:{
Priority = 24575
}

But it doesn't fire. Can anyone tell me what the problem is? It's
implemented in C# with interop. Any comment will be greatly appreciated.

Thanks a lot in advance
Stanley