1 /etc/postfix/main.cf:
     2     mynetworks = 127.0.0.0/8 12.34.56.0/24
     3     relay_domains = example.com
     4     parent_domain_matches_subdomains =
     5         debug_peer_list smtpd_access_maps
     6     smtpd_recipient_restrictions =
     7         permit_mynetworks reject_unauth_destination
     8
     9     relay_recipient_maps = hash:/etc/postfix/relay_recipients
    10     transport_maps = hash:/etc/postfix/transport
    11
    12 /etc/postfix/relay_recipients:
    13     user1@example.com   x
    14     user2@example.com   x
    15      . . .
    16
    17 /etc/postfix/transport:
    18     example.com   smtp:[inside-gateway.example.com]