The Domain Name System (DNS) is a hierarchical naming system that can map domain names to IP addresses and other information. DNS is essential to the operation of the internet, and it allows users to access websites, send and receive email, and use other online services.
Two common types of DNS records are A and MX, which serve different purposes. In this article, we will explore the differences between DNS A records and MX records.
A DNS A record maps a domain name to an IP address. When a user types a domain name into their web browser, the DNS resolver queries the DNS server for the IP address associated with the domain name.
The DNS server responds with the IP address, and the web browser uses it to connect to the web server and display the website.
The format of a DNS A record is as follows:
For example, if you wanted to map the domain name “example.com” to the IP address “192.0.2.1,” you would create the following A record:
The “IN” stands for “Internet” and indicates the class of the record. The “A” indicates the type of record, an IPv4 address. The IPv4 address is specified as four decimal numbers separated by periods, such as “192.0.2.1.”
A DNS MX record is used to specify the mail server responsible for handling email messages for a domain name. When a user sends an email to an address at a domain name, the sender’s mail server queries the DNS server for the MX record associated with the domain name.
The DNS server responds with the mail server’s hostname, and the sender’s mail server uses it to deliver the email.
The format of a DNS MX record is as follows:
For example, if you wanted to specify that the mail server responsible for handling email messages for “example.com” is “mail.example.com,” you would create the following MX record:
The “10” indicates the priority of the mail server. If multiple MX records are specified for a domain name, the mail server with the lowest priority number is tried first. If that server is unavailable, the next server with the following highest priority number is tried, and so on.
While DNS A records and MX records both serve essential functions in the DNS system, there are several key differences between them.
Many reputable web hosts offer control panels that allow easy management of hosting settings. That includes DNS records such as A and MX records. However, how these control panels handle A and MX records can differ depending on the hosting provider and control panel software used.
A records are typically managed through a section of the control panel dedicated to DNS management. Users can view, edit, and add A records for their domain names in this section. The user can typically enter the hostname (such as “www” or “mail”), the IP address of the server where the website or service is hosted, and the time-to-live (TTL) value.
Some control panels may offer advanced settings such as wildcard A records or reverse DNS.
MX records are also managed through the DNS management section of the control panel but may be located in a separate sub-section specifically for email routing. The user can view, edit, and add MX records for their domain name in this section.
The user can enter the mail server’s hostname, the priority value, and the server’s IP address where the mail server is hosted. Some control panels may offer advanced settings such as mail exchanger weighting or backup MX servers.
Some web hosting control panels may offer additional features or integrations for managing A and MX records, such as automated DNS management, DNS templates, or third-party DNS services.
Understanding the differences between DNS A and MX records is essential for adequately configuring domain name resolution and email routing.
While A records map domain names to IP addresses for web servers and other services, MX records specify the mail server responsible for handling email messages for a domain name. Both records are essential for proper website function in delivering web and email services to users.
By understanding the data stored, format, priority, and usage frequency differences between A and MX records, website owners can correctly configure their DNS settings for optimal performance and reliability.