Node.js - dnsPromises.resolveMx() Method

The dnsPromises.resolveMx() method uses the DNS protocol to resolve the mail exchange records (MX Records) for the hostname. The promise is resolved with an array of objects containing both a priority and exchange property on success.

Syntax

dnsPromises.resolveMx( hostname )

where, hostname is the parameter that takes the input for the hostname to be resolved.

Example 1

Create a file with the name "resolveMx.js" and copy the following code snippet. After creating the file, use the command "node resolveMx.js" to run this code as shown in the example below −

// dns.resolveMx() Demo Example

// Importing the dns module
const dns = require('dns');

const dnsPromises = dns.promises;

// Passing IP to find the hostname TXT records
dnsPromises.resolveMx('tutorialspoint.com').then((response) => {
   console.log("MX Records: ", response);
})

Output

C:\home\node>> node resolveMx.js
MX Records: [ { exchange: 'alt3.aspmx.l.google.com', priority: 10 },
   { exchange: 'alt2.aspmx.l.google.com', priority: 5 },
   { exchange: 'alt1.aspmx.l.google.com', priority: 5 },
   { exchange: 'aspmx.l.google.com', priority: 1 },
   { exchange: 'alt4.aspmx.l.google.com', priority: 10 } ]

Example 2

// dns.resolveMx() Demo Example

// Importing the dns module
const dns = require('dns');

const dnsPromises = dns.promises;

// Setting ttl as true
const options={
   ttl:true,
};

// Calling dnsPromises.resolveMx() method
// asynchronously
(async function() {

   const records = await dnsPromises.resolveMx('google.com', options);

   // Printing records
   console.log("MX Records: ", records);
})();

Output

C:\home\node>> node resolveMx.js
MX Records: [ { exchange: 'alt4.aspmx.l.google.com', priority: 50 },
   { exchange: 'aspmx.l.google.com', priority: 10 },
   { exchange: 'alt3.aspmx.l.google.com', priority: 40 },
   { exchange: 'alt1.aspmx.l.google.com', priority: 20 },
   { exchange: 'alt2.aspmx.l.google.com', priority: 30 } ]