Node.js dnsPromises.resolveMx() Method
Last Updated :
13 Oct, 2021
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The dnsPromises.resolveMx() method is an inbuilt application programming interface of promises object of the dns module which is used to resolve MX or mail exchange records for the specified hostname using DNS protocol.
Syntax:
javascript
Output:
javascript
Output:
dnsPromises.resolveMx( hostname )Parameters: This method accepts a single parameter as mentioned above and described below:
- hostname: this parameter specifies a string which denotes the hostname to be resolved.
// Node.js program to demonstrate the
// dnsPromises.resolveMx() method
// Accessing promises object from dns module
const dns = require('dns');
const dnsPromises = dns.promises;
// Calling dnsPromises.resolveMx() method
dnsPromises.resolveMx('google.com').then((res) => {
console.log("for google : ");
console.log(res);
});
for google :
[ { exchange: 'alt4.aspmx.l.google.com', priority: 50 },
{ exchange: 'alt3.aspmx.l.google.com', priority: 40 },
{ exchange: 'aspmx.l.google.com', priority: 10 },
{ exchange: 'alt1.aspmx.l.google.com', priority: 20 },
{ exchange: 'alt2.aspmx.l.google.com', priority: 30 } ]
Example 2:
// Node.js program to demonstrate the
// dnsPromises.resolveMx() method
// Accessing promises object from dns module
const dns = require('dns');
const dnsPromises = dns.promises;
// Calling dnsPromises.resolveMx() method
// asynchronously
(async function() {
// Records from resolveMx function
const records = await dnsPromises.resolveMx(
'geeksforgeeks.org');
// Printing records
console.log("from async: ");
console.log(records);
})();
from async:
[ { exchange: 'aspmx.l.google.com', priority: 1 },
{ exchange: 'alt3.aspmx.l.google.com', priority: 10 },
{ exchange: 'alt4.aspmx.l.google.com', priority: 10 },
{ exchange: 'alt1.aspmx.l.google.com', priority: 5 },
{ exchange: 'alt2.aspmx.l.google.com', priority: 5 } ]
Note: The above program will compile and run by using the node index.js command.
Reference: https://nodejs.org/api/dns.html#dns_dnspromises_resolvemx_hostname
