curl -X POST 'https://api.resend.com/inboxes/inbox-id/drafts/draft-id/send' \
  -H "Authorization: Bearer $RESEND_API_KEY" \
  -H 'User-Agent: my-app/1.0' \
  -H 'Content-Type: application/json' \
  -d '{
  "headers": {
    "X-Ticket-Id": "4821"
  }
}'

# POST /inboxes/{inbox_id}/drafts/{draft_id}/send (Resend API)
Base URL: https://api.resend.com
Auth: Authorization: Bearer <RESEND_API_KEY>
Last verified: 2026-10-20

> Send a draft

## Critical Gotchas
* All requests must include a `User-Agent` header (e.g. `User-Agent: my-app/1.0`) or the API returns HTTP 403.

## cURL
curl -X POST 'https://api.resend.com/inboxes/inbox-id/drafts/draft-id/send' \
  -H "Authorization: Bearer $RESEND_API_KEY" \
  -H 'User-Agent: my-app/1.0' \
  -H 'Content-Type: application/json' \
  -d '{"headers":{"X-Ticket-Id":"4821"}}'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| inbox_id | path | string | Yes | The Inbox ID or the inbox email address, such as `support... |
| draft_id | path | string | Yes | The Draft ID. |
| headers | body | object | No | Custom headers to add to the email. The `In-Reply-To`, `R... |

## Response (200 OK)
{"id":"6a0c8e58-3d9e-4f7a-8b14-2e3f4a5b6c71"}

---
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POST

POST /inboxes/{inbox_id}/drafts/{draft_id}/send — Resend API

Resend API

Send a draft

Base URL: https://api.resend.com
Auth: Authorization: Bearer <RESEND_API_KEY>
Last verified: 2026-10-20 · upstream hash matched

Actions Try in browser→

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Critical gotchas

All requests must include a User-Agent header (e.g. User-Agent: my-app/1.0) or the API returns HTTP 403.

cURL

curl -X POST 'https://api.resend.com/inboxes/inbox-id/drafts/draft-id/send' \  -H "Authorization: Bearer $RESEND_API_KEY" \  -H 'User-Agent: my-app/1.0' \  -H 'Content-Type: application/json' \  -d '{  "headers": {    "X-Ticket-Id": "4821"  }}'

Parameters

Name	In	Type	Required	Description
inbox_id	path	string	Yes	The Inbox ID or the inbox email address, such as `[email protected]`. A value that contains `@` must be a valid email address, and any other value must be a UUID, or the request returns a 422. The address match is case-insensitive and never falls back to the inbox `name`. An address that matches no inbox returns a 404.
draft_id	path	string	Yes	The Draft ID.
headers	body	object	No	Custom headers to add to the email. The `In-Reply-To`, `References` and `Reply-To` headers are set by Resend and cannot be set here. Sending one of them, in any letter case, returns a 422. Header names cannot be empty, and names and values cannot contain line breaks or null characters, or the request returns a 422. `null` means no custom headers.

Response 200 OK

{
  "id": "6a0c8e58-3d9e-4f7a-8b14-2e3f4a5b6c71"
}

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