delivery_rules and RR records ...

I'm curious as to how often DNS happens in relation to delivery_rules ...
right now, I have a whack of relay hosts for our mailing lists, so that we
get a bit more local for delivery ... ppl are noticing the improvement,
but my delivery_rules look like a mess ...

What I'd like to do is setup an RR record in DNS and just have that one
"host" assigned to an area ... would that be as effective as listing the
hosts in delivery rules, or is the DNS somehow cached/loaded up when the
process starts and only checked again on next restart?

Sorry, can't quite seem to get a good wording on that ... basically, is
there any difference listing all hosts in delivery_rules for a specific
rule, vs setting up a RR record for them ... ?

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: [email protected]           Yahoo!: yscrappy              ICQ: 7615664