Email failed error: "The from address does not match a verified Sender Identity. Mail cannot be sent..."

Problem statement

The customer set up Sendgrid as their SMTP provider and found they were not receiving passwordless emails. They had “Failed Notification” (type: fn) entries in their tenant logs with the following error description:

The from address does not match a verified Sender Identity. Mail cannot be sent until this error is resolved. Visit https://sendgrid.com/docs/for-developers/sending-email/sender-identity/ to see the Sender Identity requirements

Cause

In the Email passwordless connection settings, the ‘From’ email was set to <root@auth0.com>.

Solution

Navigate to Dashboard > Authentication > Passwordless, click on Email and add an email address that is registered as a Sender Identity with Sendgrid in the ‘From’ field.