SQL per-user config: access sender info in $sql_select_policy

[William Wilhelm via amavis-users]

Hi,

I've got per-recipient config working well but since amavis is also 
scanning outgoing mail, I think it would make sense to have "per-sender" 
config as well, in the case where the sender is local.

Is there some way to configure this? Really I think I only need the ability 
to refer to the sender in the $sql_select_policy query. Similarly to the %k 
placeholder which contains all things recipient. A skim of the code gave a 
glimmer of hope for %s, but that's not it.

Thanks,
Will