antony: 

the only reason why i am doing this is because i am 
blocking all incoming connectios to my box except 
portuguese connections. i manage to get all the 
portuguese ip ranges, put the forward chain to drop 
and a accepted all the sources i want to get 
connections from. this way i will only be accepting 
connetions from portugal, since that the ammount of 
users i administrate is not enough for that machine to 
be opened to the whole world. 

there are in fact lots of users expecting mail to come 
from those 2 most known smtps, so this forces me to 
accept connectiosn from those domains :))

the way i see it, filtering with qmail doesn´t make 
any sense, because what i want is not to filter but to 
accept :)))