Not really any steps apart from integrated it in your / etc / postfix / main.cf:
smtpd_recipient_restrictions =
#check_policy_service inet:127.0.0.1:10031,
permit_sasl_authenticated,
permit_mynetworks,
check_client_access hash:/etc/postfix/sender_whitelist,
check_client_access hash:/etc/postfix/sender_blacklist,
check_client_access hash:/etc/postfix/rbl_override,
reject_unauth_destination,
reject_non_fqdn_sender,
reject_non_fqdn_recipient,
reject_unknown_recipient_domain,
reject_rbl_client YOURDQAPIKEYHERE.zen.dq.spamhaus.net=127.0.0.[2..11],
reject_rbl_client cn.country.spameatingmonkey.net,
reject_rbl_client kp.country.spameatingmonkey.net,
reject_rbl_client ng.country.spameatingmonkey.net,
reject_rbl_client ru.country.spameatingmonkey.net,
reject_rbl_client tr.country.spameatingmonkey.net