On Thu, Sep 07, 2000 at 12:03:55PM +0200, Jost Krieger wrote:
> On Thu, Sep 07, 2000 at 01:48:00AM -0400, Adam McKenna wrote:
>
> > 2) It is *not* the frigging MX record. That has nothing to do with it. Any
> > mailer that breaks when there is only an A record is a broken mailer.
>
> And who says so? I'm sure every mailer SHOULD fall back to the A record,
> but the RFCs don't demand it.
RFC 974 January 1986
Mail Routing and the Domain System
[snip]
Issuing a Query
The first step for the mailer at LOCAL is to issue a query for MX RRs
for REMOTE. It is strongly urged that this step be taken every time
a mailer attempts to send the message. The hope is that changes in
the domain database will rapidly be used by mailers, and thus domain
administrators will be able to re-route in-transit messages for
defective hosts by simply changing their domain databases.
[snip]
If the response does not contain an error response, and does not
contain aliases, its answer section should be a (possibly zero
length) list of MX RRs for domain name REMOTE (or REMOTE's true
domain name if REMOTE was a alias). The next section describes how
this list is interpreted.
Interpreting the List of MX RRs
NOTE: This section only discusses how mailers choose which names to
try to deliver a message to, working from a list of RR's. It does
not discuss how the mailers actually make delivery.
[snip]
It is possible that the list of MXs in the response to the query will
be empty. This is a special case. If the list is empty, mailers
should treat it as if it contained one RR, an MX RR with a preference
value of 0, and a host name of REMOTE.
Thanks for playing.
--Adam
