# Pointer record (PTR)

*Internet standard*. A DNS record that maps an IP address to one hostname in a domain. It is also known as a reverse DNS record.

To configure [reverse DNS][rDNS] for your dedicated IP address in Twilio SendGrid, add a [CNAME record][cname] to your DNS server.

## Related entries

* [Mail Exchanger record (MX)][mx]
* [Domain Name System (DNS)][dns]
* [Fully Qualified Domain Name][fqdn]
* [Troubleshooting Sender Authentication][tb-sender-authn]

[cname]: /docs/sendgrid/glossary/cname

[mx]: /docs/sendgrid/glossary/mx-record

[dns]: /docs/sendgrid/glossary/dns

[fqdn]: /docs/sendgrid/glossary/fqdn

[rDNS]: /docs/sendgrid/ui/account-and-settings/how-to-set-up-reverse-dns

[tb-sender-authn]: /docs/sendgrid/ui/account-and-settings/troubleshooting-sender-authentication