OS X Mountain Lion Server For Dummies

Mail Service and the Internet: DNS

If you want your e-mail server to send and receive mail over the Internet, you will need an Internet domain name (which ends in .com, .org, .net, or others) and DNS service.

You can buy a domain name at a domain name registrar such as www.networksolutions.com or www.godaddy.com. If you own a domain name for a website, you can use it for e-mail as well. If you set up your server with a .local or .private domain name, you’ll need to reconfigure it with an Internet domain. You change the host name in the Network tab of the Server app’s server pane. If you change the host name, you must change any DNS settings that you may have for the server.

DNS service can run on your Mountain Lion Server Mac, on another server in your organization, or elsewhere, such as at your ISP or at the Internet registrar where you obtained your domain name.

How MX records help send e-mail

An SMTP server sending a message looks at the domain name of the e-mail message and asks a DNS server for the corresponding IP address of an e-mail server — either the final destination server or an intermediate e-mail server on the Internet. The DNS server looks up the domain name in an MX record and then sends the IP address back to the SMTP server. The SMTP server can then send on the e-mail message. MX records can list multiple IP addresses for a given domain name, ranked in order for the SMTP server to try.

Regardless of where you host your DNS service, you will need to create a ...