On Fri, 26 Jan 2007, Jethro R Binks wrote:
> On Fri, 26 Jan 2007, W B Hacker wrote:
>
> > Understanding that all you want to publish is the mailserver, it is
> > still, just IMNSHO, not necessarily a 'good thing' to have no 'A' record
> > for the bare <domain>.<tld>. i haven't researched whether it is is / is
> > not a standards violation, but lots of things rely on the'A' recpord for
> > the 'raw' <domain>.<tld> and some of these MAY be used by SOME
> > mailservers - ident callouts, to name one.
It is not a standards violation. Indeed, the original reason for the
invention of MX ("Mail eXchange") records was for getting email from the
Internet to hosts that were not on the Internet, but were on some other
network - and which therefore by definition could not have A records.
> So I would love to hear of a good reason for needing, or desirability for
> having, an A record called 'strath.ac.uk'.
We do not have, and as far as I know never have had, an A record for
'cam.ac.uk'.
One of our systems, cus.cam.ac.uk, does have both A and MX records,
with the MX records not pointing to the same hosts (they point to our
central mailers that scan before passing the messages on). Our logs are
full of attempts to deliver mail directly to the IP addresses,
presumably gleaned from the A records. Such attempts are rejected, of
course.
--
Philip Hazel University of Cambridge Computing Service
Get the Exim 4 book: http://www.uit.co.uk/exim-book
