Except that if these hosts had any other DNS records (such as A or CNAME)
the wildcard MX record would be ignored. They are only valid for names
which have no other records at all. This seems to be a little known
aspect of DNS.
[UK aside: This is why I have repeatedly disputed the "easier
mail routing" argument for the <host>.<region>.uk.ampr.org names
proposed at UKIP meetings despite nobody seeming to listen! An MX for
*.<region>.uk.ampr.org won't work for hosts that have A records which
is probably all of them.]
>Why don't you deliver direct? Unless you are using the 'real' DNS you could
>even hack up a wildcard *.ampr.org MX record to point at your smarthost.
Subject to limitations in my comment above. I actually do use a few
local hacks to DNS at the moment to assist mail routing but they need
to be explicit MX entries, not wildcards.
Regards, Dave