An MX (Mail Exchange) record is a type of DNS (Domain Name System) record that specifies the mail server responsible for receiving email messages on behalf of a domain. It plays a critical role in directing email traffic by telling email servers where to deliver emails for a specific domain. Without an MX record, email delivery to that domain would not be possible.
When someone sends an email to an address like user@example.com, the sending email server queries the DNS for the MX record of example.com. The MX record provides the hostname of the mail server (e.g., mail.example.com) that should receive the email.
Priority System: MX records can include a priority value (a number), where a lower number indicates a higher priority. If multiple MX records exist for a domain, the mail server with the lowest priority number is tried first. If it’s unavailable, the next lowest priority server is attempted.
Example:
example.com IN MX 10 mail1.example.com
example.com IN MX 20 mail2.example.com
Here, mail1.example.com (priority 10) is the primary server, and mail2.example.com (priority 20) is the backup.
Load Balancing: If multiple MX records have the same priority, email traffic can be distributed across those servers for load balancing.
Essential for Email: Without an MX record, there’s no way for email servers to know where to send messages for a domain.
For the domain example.com, an MX record might look like this in DNS configuration:
example.com IN MX 10 mail.example.com.
10 is the priority.
mail.example.com is the mail server’s hostname.
MX records ensure that emails reach the correct destination efficiently and reliably, making them a fundamental part of email communication on the internet.
Without an MX record, your domain can’t receive email.
They point email traffic to your email provider (like Google Workspace, Microsoft 365, Zoho, etc.).
