Mx mail exchanger
A mail exchanger (MX) record is a type of DNS record that specifies the mail server responsible for accepting email messages on behalf of a domain name. Here's a breakdown of MX records:
What is an MX record?
An MX record is a DNS record that maps a domain name to a mail server's hostname or IP address. It's used to determine which mail server should receive email messages intended for a specific domain.
Format of an MX record
An MX record consists of two parts:
- Priority: A numerical value that indicates the order in which mail servers should be tried. Lower values have higher priority.
- Mail server hostname or IP address: The hostname or IP address of the mail server responsible for accepting email messages.
Example of an MX record
Here's an example of an MX record:
IN MX 10 mail.example.com.
In this example:
IN
specifies that this is an MX record.MX
specifies the type of record.10
is the priority value, indicating that this mail server should be tried first.mail.example.com
is the hostname of the mail server responsible for accepting email messages.
How MX records work
When an email message is sent to a domain, the sending mail server performs a DNS lookup to determine the MX record for that domain. The MX record specifies the mail server responsible for accepting email messages, and the sending mail server uses this information to route the email message to the correct mail server.
Why are MX records important?
MX records are crucial for ensuring that email messages are delivered correctly to the intended recipient's mail server. Without a valid MX record, email messages may not be delivered or may be routed to the wrong mail server, leading to delivery failures or delays.
Common MX record issues
Some common issues that can occur with MX records include:
- Missing or incorrect MX records
- Duplicate or conflicting MX records
- Incorrect priority values
- Mail servers not responding to DNS queries
Tools for managing MX records
There are several tools available for managing MX records, including:
- DNS management tools like DNSimple, Cloudflare, or Amazon Route 53
- Email hosting providers like Gmail, Microsoft 365, or Zoho Mail
- DNS record editors like dig or nslookup