Twilio SendGrid Reverse DNS API

The Twilio SendGrid Reverse DNS API (formerly IP Whitelabel) allows you to configure reverse DNS settings for your account. Mailbox providers verify the sender of your emails by performing a reverse DNS lookup.When setting up Reverse DNS, Twilio SendGrid will provide an A Record (address record) for you to add to the DNS records of your sending domain. The A record maps your sending domain to a dedicated Twilio SendGrid 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.Reverse DNS is available for [dedicated IP addresses](https://sendgrid.com/docs/ui/account-and-settings/dedicated-ip-addresses/) only.You can also manage your reverse DNS settings in the Sender Authentication setion of the [Twilio SendGrid application user interface](https://app.sendgrid.com/settings/sender_auth).See [**How to Set Up Reverse DNS**](https://sendgrid.com/docs/ui/account-and-settings/how-to-set-up-reverse-dns/) for more information.