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.
Set up reverse DNS
POST /v3/whitelabel/ips
Base url: https://api.sendgrid.com
This endpoint allows you to set up reverse DNS.
Authentication
- API Key
Headers
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.
Request Body
The IP address for which you want to set up reverse DNS.
The subdomain that will be used to send emails from the IP address. This should be the same as the subdomain used to set up an authenticated domain.
The root, or sending, domain that will be used to send message from the IP address.
{
"ip": "192.168.1.1",
"subdomain": "email",
"domain": "example.com"
}Responses
The ID of the Reverse DNS.
The IP address that this Reverse DNS was created for.
The reverse DNS record for the IP address. This points to the Reverse DNS subdomain.
The users who are able to send mail from the IP address.
The username of a user who can send mail from the IP address.
The ID of a user who can send mail from the IP address.
The subdomain created for this reverse DNS. This is where the rDNS record points.
The root, or sending, domain.
Indicates if this is a valid Reverse DNS.
Indicates if this Reverse DNS was created using the legacy whitelabel tool. If it is a legacy whitelabel, it will still function, but you'll need to create a new Reverse DNS if you need to update it.
A Unix epoch timestamp representing the last time of a validation attempt.
Indicates if the a_record is valid.
The type of DNS record.
This is the web address that will be mapped to the IP address.
The IP address being set up with Reverse DNS.
{
"id": 1,
"ip": "192.168.1.1",
"rdns": "o1.email.example.com",
"users": [
{
"username": "john@example.com",
"user_id": 7
},
{
"username": "jane@example.com",
"user_id": 8
}
],
"subdomain": "email",
"domain": "example.com",
"valid": true,
"legacy": false,
"a_record": {
"valid": true,
"type": "a",
"host": "o1.email.example.com",
"data": "192.168.1.1"
}
}Need some help?
We all do sometimes. Get help now from the Twilio SendGrid Support Team.
Running into a coding hurdle? Lean on the wisdom of the crowd by browsing the SendGrid tag on Stack Overflow or visiting Twilio's Stack Overflow Collective.
