Domain Warn List

The Sender Verification API exposes multiple endpoints that allow you to programmatically manage the Sender Identities that are authorized to send email for your account. You can also manage Sender Identities in the SendGrid app by selecting Sender Authentication under Settings in the navigation bar. For full app instructions, see Sender Verification.

The Sender Verification API provides a RESTful interface for creating new Sender Identities, retrieving a list of existing Sender Identities, checking the status of a Sender Identity, updating a Sender Identity, and deleting a Sender Identity.

This API offers additional endpoints to check for domains known to implement DMARC, and resend verification emails to Sender Identities that have yet to complete the verification process.

GET/v3/verified_senders/domains

Base url: https://api.sendgrid.com

This endpoint returns a list of domains known to implement DMARC and categorizes them by failure type — hard failure or soft failure.

Domains listed as hard failures will not deliver mail when used as a Sender Identity due to the domain's DMARC policy settings.

For example, using a yahoo.com email address as a Sender Identity will likely result in the rejection of your mail. For more information about DMARC, see Everything about DMARC.