Debian Stretch: restrict SMTPD in Postfix

We use Sorbs.net and SpamCop.net service for restrict our SMTPD in postfix.

Add/edit /etc/postfix/main.cf:
...
smtpd_recipient_restrictions = reject_invalid_hostname, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, permit_mynetworks, reject_unauth_destination, reject_rbl_client bl.spamcop.net, reject_rbl_client dnsbl.sorbs.net, permit_sasl_authenticated
...

Restart your postfix
# service postfix restart

Watch your postfix status
# service postfix status

References:

• http://www.sorbs.net/mailsystems/postfix-2.3.shtml 
• https://www.spamcop.net/fom-serve/cache/349.html