set skip on lo0
table <spamd>           persist
table <spamd-white>     persist
#rdr pass on em0 proto tcp from <spamd> to !lo0 port smtp -> lo0 port spamd
#rdr pass on em0 proto tcp from !<spamd-white> to !lo0 port smtp -> lo0 port spamd
rdr pass on em0 proto tcp from <spamd> to port smtp \
        -> 127.0.0.1 port spamd
rdr pass on em0 proto tcp from !<spamd-white> to port smtp \
        -> 127.0.0.1 port spamd