I have set up a postfix host that accepts and sends mail directly for a LAN. The last lines in /etc/postfix/main.cf are like so:
################################# smtpd_helo_required = yes smtpd_helo_restrictions = reject_invalid_hostname, reject_unknown_client, reject_unknown_hostname, reject_non_fqdn_hostname, permit_mynetworks smtpd_client_restrictions = hash:/etc/postfix/client_restrictions, reject_unknown_client, reject_rbl_client cbl.abuseat.org, reject_rbl_client zen.spamhaus.org maps_rbl_domains = bl.spamcop.net, rbl-plus.mail-abuse.org disable_vrfy_command = yes smtpd_recipient_restrictions = reject_invalid_hostname, reject_non_fqdn_hostname, reject_non_fqdn_sender, reject_non_fqdn_recipient, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unknown_client, reject_unknown_hostname, permit_mynetworks, reject_unauth_destination, check_recipient_access pcre:/etc/postfix/recipient_checks.pcre, check_helo_access hash:/etc/postfix/helo_checks, check_sender_access hash:/etc/postfix/sender_checks, check_client_access hash:/etc/postfix/client_checks, check_client_access pcre:/etc/postfix/client_checks.pcre, reject_rbl_client cbl.abuseat.org, reject_rbl_client zen.spamhaus.org, permit smtpd_data_restrictions = reject_unauth_pipelining, permit ################################# It works but I suspect it needs some corrections and tuning. Any suggestions and comments are welcome.