Bypass spam check for message from my local domain

[Scappatura Rocco]

Hello.

In my amavid-new configuration I have:

@local_domains_acl = (
  ".$mydomain" ,
  read_hash('/etc/postfix/relay_domains')
);

@local_domains_maps = @local_domains_acl;

I would like to avoid spam check for all message with sender listed in 
@local_domain_maps.

How could I set up a such behaviour?

Regards,

RS