What are MX Records?
MX records are used by mail servers to determine where to deliver email for a domain. If no email is sent or received from a domain, then there is no reason to have MX records configured within the domain. MX records are ordered based on MX priority. The lowest priority MX record is the first destination for email. MX records should only map to A records in a domain (not CNAME records), or other external mail servers to the domain. If email is sent to a domain with no MX records, mail delivery will be attempted to the matching A record. For example, if the domain example.com had no MX records, mail would be delivered the A record for example.com (if it exists).
MX Record Failover
How to Configure MX Records
1.Select Managed DNS and click on Domains.
2. Select the Domain Name you want to add an MX record too.
MX Record Fields
A) Name: Enter a name for the record. Please note, in most cases the name field of the record is left blank for MX records.
B) TTL: The TTL (Time to Live) in seconds is the length of time the record will cache in resolving name servers and web browsers. The longer the TTL, then remote systems will lookup the DNS record less frequently. Your name servers will also receive less query traffic since most queries are answered by resolving name servers. Conversely, the shorter the TTL the faster any changes you make to your DNS will propagate in servers that have cached data. However, your domain will receive more query traffic.
C) Server: Enter the destination mail server for the domain. If you point to a value external to the domain, then mail for example.com will be delivered to mx.mailserver.com. Please note, the value field must end in a dot (.) in order to keep the music.com domain from being appended to the end of the value. The tool tip at the top of the record configuration screen will display how the host will resolve.
D) MX Level: The MX Level determines the order (which mail server) that your mail will be attempted to be delivered. The mail server with the lowest MX Level will first be attempted to have the email delivered.
E) Notes: Add a helpful note with keywords so you can search for your records later.
F) Save: Save your changes. Don’t forget to commit your changes.
Records that are static and don’t change often should have TTL’s set between 1800 (being on the low end) to 86400 seconds (30 minutes to 1 day cache).
Records configured with Failover or that change often should have TTL’s set anywhere from 180 to 600 (3 to 10 minutes cache).
If a change is needed for a record with a high TTL, then the TTL can be lowered prior to making the change and then raised back up again after the changes were made.