Catch All Server - Null MX Setup

[WiNNie]

Hi,

I have a catch-all Bind Name Server setup and would like to either stop
all MX lookups, not respond to them, or impliment another method of
minimizing their effect on my Name Server:

$TTL    86400
.       IN      SOA     ns2.domain. (
                        45
                        28800
                        14400
                        3600000
                        86400 )
        IN      NS      ns2.domain.
*       IN      A       1,2,3,4

Any suggestions welcome. And is there any negative effect of adding in
the MX records to point to 127.0.0.1?