relaying don't affect Rbl score ?

[Noc Phibee]

Hi

actually, i use a lot of server with spamassassin in direct MX.

I want change this for put two relay before spam scan

                                         /   Spam1
Internet ==> MX Relay  <== Spam2
                                        \    Spam3

I use DNS Round Robin for MX Relay sent at all spam server.

I want know if in this solution, that don't  change Rbl Score ?
he use the IP of the sender, not of my relay, it's correct ?

Thanks bye