Reverse DNS (formerly IP Whitelabel) allows mailbox providers to verify the sender of an email by performing a reverse DNS lookup upon receipt of the emails you send.
Reverse DNS is available for dedicated IP addresses only.
When setting up reverse DNS, Twilio SendGrid will provide an A Record (address record) for you to add to your DNS records. The A Record maps your sending domain to a dedicated Twilio SendGrid IP address.
A Reverse DNS consists of a subdomain and domain that will be used to generate a reverse DNS record for a given IP address. Once Twilio SendGrid has verified that the appropriate A record for the IP address has been created, the appropriate reverse DNS record for the IP address is generated.
You can also manage your reverse DNS settings in the Sender Authentication setion of the Twilio SendGrid App.
For more about Reverse DNS, see "How to set up reverse DNS" in the Twilio SendGrid documentation.
This endpoint allows you to validate a reverse DNS record.
Always check the valid property of the response’s validation_results.a_record object. This field will indicate whether it was possible to validate the reverse DNS record. If the validation_results.a_record.valid is false, this indicates only that Twilio SendGrid could not determine the validity your reverse DNS record — it may still be valid.
If validity couldn’t be determined, you can check the value of validation_results.a_record.reason to find out why.
You can retrieve the IDs associated with all your reverse DNS records using the "Retrieve all reverse DNS records" endpoint.
Bearer <<YOUR_API_KEY_HERE>>Optional
The on-behalf-of header allows you to make API calls from a parent account on behalf of the parent's Subusers or customer accounts. You will use the parent account's API key when using this header. When making a call on behalf of a customer account, the property value should be "account-id" followed by the customer account's ID (e.g., on-behalf-of: account-id <account-id>). When making a call on behalf of a Subuser, the property value should be the Subuser's username (e.g., on-behalf-of: <subuser-username>). See On Behalf Of for more information.
The ID of the reverse DNS record that you would like to validate.
The ID of the reverse DNS record.
Indicates if the reverse DNS record is valid.
truefalseThe specific results of the validation.
1const client = require("@sendgrid/client");2client.setApiKey(process.env.SENDGRID_API_KEY);34const id = "ZGkrHSypTsudrGkmdpJJ";56const request = {7url: `/v3/whitelabel/ips/${id}/validate`,8method: "POST",9};1011client12.request(request)13.then(([response, body]) => {14console.log(response.statusCode);15console.log(response.body);16})17.catch((error) => {18console.error(error);19});