Mark Martinec <mark.martinec...@ijs.si> writes: > The only place that such loss can be prevented is to check > that the sending domain has its MX or A or AAAA record, > right away while the message is being received. > It is prudent to reject such unbouncible mail right away, > before even accepting it. This is the only opportunity that > the sender can be made aware of the problem.
Should AAAA records not only be checked if the receiving domain has the capability of sending mail using IPv6? Otherwise mail received via IPv4 from a domain which only publishes an AAAA record would also be unbouncible. What also of a domain which has MX record(s) but the hosts pointed to by those MX records only have AAAA records not A records? Mail from those domains would also be unbouncible if sent to an IPv4 only recipient.
