I posted something about this before but I had some additional questions.
We have an Exchange server here onsite. We have an ISP that is also hosting our website offsite.
I am switching our ISP and web hosting to two different companies. (our domain name is with another different company, I would have to change the NS records to reflect the new hosting co.)
Now, to prevent any downtime, or a minimal amount of it, could I have our MX records changed to our old IP and also have our new IP listed as well and do the same with our NS records, so that during the switch to our new ISP and hosting company we would have little to no downtime and if I encounter any problems I could just switch back to the old ISP and have everything keep functioning?
Also, is our MX record just our IP Address where the Exchange server resides? I'm not exactly sure on that.
I know our NS records will have to point to the new hosting co.