Many of you probably already know this information, but just in case
it helps someone...
I stumbled across a white paper re: DNS configuration on the
software.com web site. It's pretty generic and doesn't specifically
call out software.com products (too much).
It is called:
Configuring DNS for Your Mail Service
How to avoid the most common misconfigurations
is available at <http://www.software.com/whitepapers>. A MS Word
This white paper outlines several strategies for configuring DNS and a
system to ensure that it remains flexible. Flexible configurations
the effort required (and support cost incurred) when upgrading a mail