Our company is moving offices and we're signing up for an new Internet provider. We self host web and email servers at static public IP addresses - these need to be moved to the new offices. My belief is that if we update the records the day of the move, then we'll see a service outage until the record changes are propagated to DNS servers worldwide.
We'd like to switch off servers at the old site and have, people instantly redirected to servers at the new site. Is it possible to setup records with our DNS service ahead of the move so that if someone contacts www.mysite.com and there's no response from the server at the old IP adderss, then the second (new site) IP address is used?
Same question for MX records and A records.
What special sauce do I need to specify?