&allow_service_for(ldap,mail);

&def_service(smtp, mail, tcp, 25);
&def_service(submission, mail, tcp, 587);
&def_service(imap, mail, tcp, 143);
&def_service(sieve, mail, tcp, 4190);
&def_service(dsync, mail, tcp, 4170);

&forward_to_service(smtp, tcp, 25);
&forward_to_service(submission, tcp, 587);
&forward_to_service(imap, tcp, 143);
&forward_to_service(sieve, tcp, 4190);
&forward_to_service(dsync, tcp, 4170);

@def $mail_ip4 = @resolve(mail, A);
@def $mail_ip6 = @resolve(mail, AAAA);
domain (ip ip6) table filter chain FORWARD interface $bridge saddr @ipfilter(($mail_ip4 $mail_ip6)) protocol tcp dport smtp ACCEPT;