Reverse DNS
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.
Validate a reverse DNS record
POST /v3/whitelabel/ips/{id}/validate
Base url: https://api.sendgrid.com
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.
Authentication
- API Key
Headers
Path Parameters
The ID of the reverse DNS record that you would like to validate.
default: NoneResponses
The ID of the reverse DNS record.
Indicates if the reverse DNS record is valid.
Allowed Values: true, falseThe specific results of the validation.
Indicates if the reverse DNS record could be validated.
Allowed Values: true, falseThe reason the reverse DNS record could not be validated. Is null if the reverse DNS record was validated.
The error messages for the failed validation.
A message describing why the reverse DNS could not be validated.
The error messages for the failed validation.
A message describing why the IP whitelabel could not be validated.
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