When it triggers
This event fires when SendKit is unable to send the email. This can happen due to internal errors, invalid configurations, or issues with the sending infrastructure.Payload
Payload fields
Unique identifier of the email.
Sender email address.
Recipient email address.
Email subject line.
Tags associated with the email. Each tag has
name and value string fields. Returns an empty array if no tags were set.ISO 8601 timestamp of when the email was created.

