I'm hosting an E-mail server (and web server) for a client of mine. It has about four different domains on currently. I want to have redundant Internet connections, so I now have a static IP address from the cable company (primary connection) and a static IP from a DSL line from the phone company. My question is, how is the best way to set up the DNS, MX records, routers, etc. to have the quickest cut-over should my primary Internet connection go down? Server is running RedHat Enterprise 5.