add reject_unlisted_recipient before greylisting, fixes #127

setup/mail-postfix.sh

@@ -124,9 +124,11 @@ tools/editconf.py /etc/postfix/main.cf \
 # reject_non_fqdn_sender: Reject not-nice-looking return paths.
 # reject_unknown_sender_domain: Reject return paths with invalid domains.
 # reject_rhsbl_sender: Reject return paths that use blacklisted domains.
-# permit_sasl_authenticated: Authenticated users (i.e. on port 587).
-# permit_mynetworks: Mail that originates locally.
+#
+# permit_sasl_authenticated: Authenticated users (i.e. on port 587) can skip further checks.
+# permit_mynetworks: Mail that originates locally can skip further checks.
 # reject_rbl_client: Reject connections from IP addresses blacklisted in zen.spamhaus.org
+# reject_unlisted_recipient: Although Postfix will reject mail to unknown recipients, it's nicer to reject such mail ahead of greylisting rather than after.
 # check_policy_service: Apply greylisting using postgrey.
 #
 # Notes:
@@ -136,7 +138,7 @@ tools/editconf.py /etc/postfix/main.cf \
 # "450 4.7.1 Client host rejected: Service unavailable". This is a retry code, so the mail doesn't properly bounce.
 tools/editconf.py /etc/postfix/main.cf \
 	smtpd_sender_restrictions="reject_non_fqdn_sender,reject_unknown_sender_domain,reject_rhsbl_sender dbl.spamhaus.org" \
-	smtpd_recipient_restrictions=permit_sasl_authenticated,permit_mynetworks,"reject_rbl_client zen.spamhaus.org","check_policy_service inet:127.0.0.1:10023"
+	smtpd_recipient_restrictions=permit_sasl_authenticated,permit_mynetworks,"reject_rbl_client zen.spamhaus.org",reject_unlisted_recipient,"check_policy_service inet:127.0.0.1:10023"
 
 # Increase the message size limit from 10MB to 128MB.
 tools/editconf.py /etc/postfix/main.cf \