In <42D5609B-B625-11D8-88FE-000A95B3BA44(_at_)hxr(_dot_)us> Andrew Newton
On Jun 4, 2004, at 7:32 AM, wayne wrote:
Now, are you suggesting that the MARID record would have to be placed
in *both* foo.com and bar.com? What if they conflict? What about
mail servers out there that depend on the falling back to A records
and have no MX records?
Good questions. The top-of-my-head answers are: 1) use the same
strategy as MX - if no MX is found, look at the spot where an A (or
AAAA) record would be,
Uh, A records have IP addresses, not domain names. Are you suggesting
looking in (or using) the in-addr tree?
2) when there are MX records, ONLY use the
one with the lowest priority. Multiple MX records of the same
priority do not match the given use case actions (in other words, in
the given use case it is unlikely that there are multiple MX records
but if there were they would all point to the same mail provider).
Hmmm... that doesn't seem obviously true to me. I would kinda like
to see data to back this up.
Anyway, my suggestion would be to instead use CNAMES or something like
SPF's "redirect" system to point control back to the mail host
provider. This would let the mail host provider create identical
stock records that all customers would need to add.