[vchkpw] How does qmail-smtp check reverse dns record for remote hosts ?

[Bulent]

 Hello 
 
 I use spamcontrol2.3 (by Erwin Hoffman) on qmail-1.03.
 I want my mail server to check reverse dns record.
 How do I have to set the qmail-smtpd/run file and tcp.smp file ?
 
 Thanks