Skip to main content

Documentation Index

Fetch the complete documentation index at: https://resend.com/docs/llms.txt

Use this file to discover all available pages before exploring further.

Event triggered whenever the email couldn’t be delivered due to a temporary issue. Delivery delays can occur, for example, when the recipient’s inbox is full, or when the receiving email server experiences a transient issue. 
{
  "type": "email.delivery_delayed",
  "created_at": "2026-02-22T23:41:12.126Z",
  "data": {
    "broadcast_id": "8b146471-e88e-4322-86af-016cd36fd216",
    "created_at": "2026-02-22T23:41:11.894719+00:00",
    "email_id": "56761188-7520-42d8-8898-ff6fc54ce618",
    "from": "Acme <onboarding@resend.dev>",
    "to": ["delivered@resend.dev"],
    "subject": "Sending this example",
    "template_id": "43f68331-0622-4e15-8202-246a0388854b",
    "tags": {
      "category": "confirm_email"
    }
  }
}