How would you even set such a thing up? I fear that you might get a couple of collusionary companies that bail each other out and smaller providers might just be left out to dry…
I do love using CloudFlare for DNS, lots of great features and generally works well, but I wish they would support AXFR for the lower tiers. I've been working on a solution for this using the CloudFlare API, but we'll see how well it works out.
However, cloudflare decision turns cloudflare "free" offering into a free SPOF. They should extend this offer to their free users, who could then use the secondary DNS that most hosts/domain name sellers provide for free to the IP that is proxified by cloudflare. It could even be limited to the case of proxy or cloudflare DNS failure, so that cloudflare could still price discriminate (make AXFR fail, unless cloudflare is down, like a dead man's switch)
That's all they did. They weren't a mail host or provider, there was no UI, nothing. All they did was allow you to specify them as, well, a secondary MX, so if you were offline they'd cache your inbound email until you were back. Simple. Efficient.
> At easyDNS we experienced so much pain from this reality that we created a system to automate flipping DNS providers at the first sign of trouble.
> We call it Proactive Nameservers, and we’re the only company in the world doing it for some reason. Maybe this is because in order to provide a service like nameserver failover, it means a company has to admit to its customers the reality that their own nameservers may at some point, fail.