Hi Dipak,
2. Have you checked this config IMG -> Event Management -> Event Messages, Status Queries, and Web Interface -> Define Criteria for Event Message Processing
The preprocessing use to manipulate data before it updates in SAP EM system. You can play with different criteria for extend preprocessing, creating event handlers, saving attachments, forward event message, saving event message etc. You can see IMG activity detail documentation available and that would give you full information about this preprocessing functionality.
Regards
GGOPII