Hi Paul,
At 02:39 31-03-2008, Paul Smith wrote:
Either:
- toaster.example.org is going to send a message with the
return-path of [EMAIL PROTECTED], in which case I'd
EXPECT toaster.example.org to have an SMTP server running on it,
hence an MX record would not be a bad thing, or
- toaster.example.org is going to send a message with a null return
path, in which case what does it matter..
The discussion have been whether the receiver should explicitly
specify a MX RR to determine whether it accepts mail. If we stretch
the MX RR requirement to a forward and reverse model, then the sender
(toaster.example.org) also has to have a MX RR. This means that the
change affects both senders and receivers. If we use a null
return-path, the sender won't know whether there was a delivery failure.
Personally, I can see a strong point for requiring MX records for
any domain which can receive mail as it removes a big ambiguity.
Anyone who doesn't set one up will soon notice that things aren't
working and will fix it. If a mail administrator is on 'talking
terms' with the DNS administrator enough to have an AAAA record
assigned to them, surely they're on talking terms enough to have an
MX record set up as well, especially since the DNS administrator
should know enough to know that one is expected.
We then have to elect whether we want a mail service as we add the
Address record. If we want to run a mail service later, it can be an
administrative burden to get the MX RR added.
Regards,
-sm
