reject_unknown_client_hostname: move into the junk folder instead of rejecting the e-mail

[Niccolò Belli]

Hi,
I'd like to use reject_unknown_client_hostname, unfortunately there are 
just too much misconfigured servers to whitelist them all :(
I do not want to just use reject_unknown_reverse_client_hostname 
instead, I'd like to mark e-mails which fail 
reject_unknown_reverse_client_hostname as spam so that I will be able to 
move them to the junk folder with sieve. Is there any way to achieve it?

Thanks,
Niccolò