If the database used by Netmail needs to be recreated because it was lost/corrupted/etc... simply run an address book sync to regain all the standard tables used by the jobs.
However the SyncAB job does not also create the tables used by the crawler (since this may not be configured in your system).
Creating the crawler-specific tables can be accomplished with a script located on the Archive server, in this location:
C:\Program Files (x86)\Messaging Architects\Crawler\dbscripts_postgres\db_pg_start.bat
Note that while this script will recreate the tables, they will not have reference IDs corresponding to existing Crawler storage locations. You will be able to create new Crawler locations, but you will not be able to use existing Crawler locations, nor use the UI to delete existing Crawler locations and their corresponding indexes.