On Fri, 2007-03-09 at 09:51 +0000, Mike Cardwell wrote:
> In my experience it would be uncommon for a mail admin to not set up
> reverse dns. However, it would be more common for a mail admin to set up
> reverse dns but not consider where the A record for it points. That's
> how I got to the differing descriptions between option 1 and 2.
There's also a boatload of small, but legitimate businesses who, in
order to save money, make do with an ADSL line and a single IP address.
They can only have one PTR record with that setup, and quite often, it
will be of the form expanded-quad.servicetype.provider.example.
When starting out with a small company, every penny costs, and having
multiple IP addresses and reverse DNS for them is far down the list.
That doesn't make their email irrelevant.
