Offtopic : Posting "to" the list, correct policy ?

[Matt Darcy]

    Guy,

I use message filters/rules to seperate the  multiple lists I subscribe 
to, the last few weeks my filters have stopped working on the server 
list (mostly), the reason for this is that 
ubuntu-server at lists.ubuntu.com is never / rarley actually in the "to" 
section of the message, normally people tend to reply to the original 
poster, then CC in the list ?

This seems like a bad idea to me as 9/10 the original poster is on the 
ubuntu-server list, and will get it the message, then get it again from 
the lists.

Is there a policy on this sort of thing for posting to the list or am I 
being over fussy ?

Matt