This seems odd to me:
if (!host_allow_relay_anywhere_set)
{
host_allow_relay_anywhere = TRUE;
if ((sender_host_accept_relay != NULL ||
sender_net_accept_relay != NULL)
&&
!verify_check_net(sender_net_accept_relay,
&sender_net_accept_relay_nets)
&&
!verify_check_host(sender_host_accept_relay,
&sender_host_accept_relay_hosts)
) host_allow_relay_anywhere = FALSE;
Now if sender_host_accept_relay is set, and sender_net_accept_relay is
null, then we call verify_check_net(NULL,...) which returns FALSE, so
host_allow_relay_anywhere is set FALSE. Right?