[Exim] Dead end addresses

I just recently changed my mail configuration over from flat files to MySQL using the vmail-sql configurations provided by Chris Lightfoot (Thanks Chris!), and I have a question. :)

I used to have a series of alias files (one for each virtual domain) that allowed me to make forwarding addresses, create a default delivery address for any unknown addresses, and (most importantly) to cause certain addresses to simply fail (e.g. spam@???).

Does anyone else do this kind of address failure using mysql? Could anyone share any ideas about setting this up again?
-- Daniel Einspanjer, daniel@??? on 05/01/2001