There are two ways to avoid the generation of the bdoc messages.
1. If you don't want the CSA* queue in CRM inbound queue and you don't want the bdocs to be generated, you could do the following steps:
Go to transaction SMW3_00
Enter the bdoc type for unwanted bdocs (You can find the bdoc type in R3AC1 for each object)
Set the indicator "do not send"
2. You could set the field Discard data indicator (DISCARDDAT) in table CRMRFCPAR for the specific object type and even for the specific load type (initial/request/delta load).
Go to transaction SM30
Enter the object type (the objects can be found in R3AC1) and the load type for unwanted bdocs
Set "X" for field DISCARDDAT
