That isn't much help for running your own DNS server though, since it's is a bit of a chicken and egg problem then. It's also hard to run a mail server on a residential connection because most of them block SMTP.

Fortunately there is another alternative, which is to get your public address from somewhere other than your local ISP. Some VPN providers offer a static IP or you can set up your own VPN to a VM on any cloud host and forward incoming traffic back over the tunnel.