Example to send forwarded mail direct to MX.
/etc/postfix/main.cf:
relayhost =
sender_dependent_relayhost_maps = pcre:/etc/postfix/relayhost_maps
/etc/postfix/relayhost_maps:
# Local domain(s) below.
/[@.]example\.com$/ postini
Another possibility may be sender_dependent_default_transport_maps.
Wietse
