In <700EEF5641B7E247AC1C9B82C05D125DA7B7(_at_)srv1(_dot_)fecyk(_dot_)ca>
"Gordon Fecyk" <gordonf(_at_)pan-am(_dot_)ca> writes:
It is my understanding that DMP requires you to fetch a TXT record
from _smtp-client.$FQDN and also an A record at
$REV-ADDRESS.$ADDRESS-TYPE._smtp-client.$FQDN. [...]
Doesn't this mean that DMP [...] require a minimum of 2 DNS queries?
More like a maximum of two, minimum of one[1].
Ok, so DMP doesn't require you to fetch *both* the TXT record and the
A record? Doesn't the TXT just say that "yes, this domain uses DMP"?
Don't you have to look up the A record also to see if the IP address
is allowed or not?
DMP got a little worse, with
a maximum of four queries, when a receiver queries for hostnames as well as
domain names. If a receiver were prepared to sacrifice Store and Forward,
that got back down to a maximum of two.
Hmmm... I don't understand this part, but maybe I just need to read
the DMP spec closer.
-wayne