[Mimedefang] Slightly OT: Advice on updating MX record (was SMTP error return after DATA?)

[Nels Lindquist]

On 9 May 2003 at 14:19, Michael Sims wrote:

<SNIP>

> BUT, I'm concerned about the amount of time it will take for my DNS
> change to propagate out to the rest of the net.  I've read that most
> see changes in 12-24 hours, a good bit in 48 hours, and some may take
> as long as 72+.  If I just switch my MX in one fell swoop then sites
> that haven't received the update will still be trying to relay mail to
> my old MX record and their connections will be rejected.  If it takes
> them a while to get the updated DNS information they may start bouncing
> mail destined for my domain. 

Your best bet is probably to temporarily lower the explicit TTL value 
on your MX RRs (incrementing the serial in the zone file, of course), 
and allow that to propogate for at least as long as your current 
default TTL.

You can then make changes, confident that they'll propogate as 
rapidly as your temporary TTL.  After everything's settled down, you 
can change back to your usual TTL to reduce traffic on your 
authoritative nameservers.

----
Nels Lindquist <*>
Information Systems Manager
Morningstar Air Express Inc.