How do I set up my email if I am using an in-house mail server and you hold our DNS?

• Many businesses use an "in-house email server" to collect email messages from the internet and route it to everyone within their company. This requires a dedicated internet address (IP address) for their email server. If they do not host their website, this requires their web server to be configured to route website traffic to one internet address (their domain name) and email to another internet address (their in-house email server). While it is possible to use a web server to collect and store email that you can view with a web browser, most businesses don't use this option. Thus - you have to configure email to go from the web server to the in-house email server.
• Configuration is handled through a DNS (Domain Name System) zone file. When you type a domain name (e.g., www.gregrobert.com ) into a web browser, or you send an email, software on the internet translates your request into an internet address using DNS, a distributed Internet directory service. Domain names exist strictly to help make the internet more humanly readable. However, internet technology uses four part "dotted IP" or "decimal IP" addresses, for example, 1.1.1.1 to uniquely identify devices connected to the internet.
• The DNS zone file itself is simply a list of configuration settings in a specified order and format. When someone requests a translation of a domain name into an internet address, the DNS zone file is searched to retrieve the correct address. Translations are either forward (from a domain name to an internet address) or reverse (from an internet address to a domain name).
• The core of the DNS file is a record type with settings. Here are the key record types you will encounter when you configure their website and email addresses:
  • SOA. The start of authority is the first record type in any DNS zone file. It provides settings for the domain name of the primary DNS server for the zone, the contact email address, a unique serial number for the zone file, and intervals for refresh, retry, expire, and time to live (TTL).
  • NS. The name server record type identifies each DNS server within a zone. Most websites have two DNS servers for redundancy backup. While the primary DNS server is listed in the SOA record type, all DNS servers must have individual NS record types. If you are a website reseller and have your own name servers, each of your name servers should have one NS record within the zone file.
  • MX. The mail exchange record type identifies the mail server(s) for your domain. You can have multiple MX record types to ensure redundancy. Settings for this record type include preference (with the lowest number having highest preference) so that any request to identify your mail server will work through your list of mail servers in the order you specify. The MX record must point to a domain name that follows the mail.gregrobert.com format.
  • A. Each MX record type also needs to have a corresponding address record type. This record type assigns the mail to a specific internet address.
  • The TTL (time to live) determines how often other parts of the DNS registry check your zone file for updates. A high setting means fewer visits and less bandwidth but also means your changes will take longer to propagate through the DNS system.
• To change your mail configuration, you only have to add an MX record type and an A address record type that included the internet address for your in-house email server. 

• In looking at this screen capture, note that all input data for record types must end with a period, for example, mail.yourdomain.com. and not mail.yourdomain.com, so that the DNS does not append data to that bit of information.

• To check that your DNS zone file is configured properly, you can use a service like DNSStuff. This free service checks your current zone file and reports back on a variety of issues with Pass, Warn, and Fail status for each issue. It tests your mail connection and lets you know if your MX and A record(s) are configured properly.