The Intersite Messaging service using the SMTP transport failed to register the event sink DLL (Ismsink.dll) with SMTP. The ...

The Intersite Messaging service using the SMTP transport failed to register the event sink DLL (Ismsink.dll) with SMTP. 
 
The event sink notifies the messaging service that new mail has arrived. New mail will accumulate in the drop folder until this problem is corrected. 
 
User Action 
Verify that Internet Information Services (IIS) is fully installed. The installation relies on proper registration of the IIS DLL (Seo.dll). 
 
Restart the Intersite Messaging service. 
 
Additional Data 
Error value:
%2 %1