AWS

Zimbra split horizon DNS on EC2 with Unbound

Email server behind NAT is a pain, but it can be further aggravated if your email server has a dynamic IP address. Which is the case with EC2. Granted, it will only change on stop/start of the instance, but still. Here’s a recipe to deal with it (a kludge, of course):

Using multiple ELBs with Cloudflare DNS

If you have an autoscaling app on EC2, you need an ELB to distribute traffic. And if you don’t trust in ELB to be HA, you need at least 2 of them. The issue is that ELBs don’t have statis IPs, they can only be referenced with CNAME. That limits your DNS hosting option to just Route53, because apex record can’t be CN...