>So, having multiple A records pointing to the same IP is ok then, when it
>comes to MX?
MX records are considered and resolved separately from A records.
With respect to the remainder of your question, reverse resolution isn't a
necessary consideration.
For example:
mail.goldblatt.net -- 208.190.130.82. It reverses to
wndrgrl.goldblatt.net. It still works.
One issue to consider, if you're using Bind, is future
maintainability. Consider what might happen if you renumber your network.
If you are using a.b.c.d notation in your MX record, you must remember to
update that record in addition to all your A records.
If you use mail.whatever.com in your MX record, you have only to update
your A record, which makes it less likely that in the event of a renumber,
you'll screw it up and cut off mail service for a week. The down side is
that this approach must, of necessity, produces another lookup for the A
record, which produces additional load on your name servers and network to
carry the UDP traffic.
ag
