[Pkg-exim4-users] Enabling DNS black list

[José de Jesús Gutiérrez Ramírez]

Hi,

I'm configuring a new installation of Exim4, and I want to enable DNS Black 
list verification, I see the next lines in the file exim4.conf.template

  .ifdef CHECK_RCPT_IP_DNSBLS
  warn
    message = X-Warning: $sender_host_address is listed at $dnslist_domain 
($dnslist_value: $dnslist_text)
    log_message = $sender_host_address is listed at $dnslist_domain 
($dnslist_value: $dnslist_text)
    dnslists = CHECK_RCPT_IP_DNSBLS
  .endif


But I don't find the definition of CHECK_RCPT_IP_DNSBLS anywhere on the file 
not even commented, it's defined in a different file?
Should I insert the definition on exim4.conf.template?
Or Should I do a different thing to make it work?

TIA

Jesus Gutierrez