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# Reschedule a scheduled email

POST https://mandrillapp.com/api/1.4/messages/reschedule
Content-Type: application/json

Reschedules a scheduled email.

Reference: https://mailchimp.com/developer/transactional/api/messages/reschedule

## Request

### Body (application/json)

This endpoint expects a MessagesRescheduleRequest.

- `key` (string, required) — A valid Mandrill API key
- `id` (string, required) — a scheduled email id, as returned by any of the messages/send calls or messages/list-scheduled
- `send_at` (string, required) — the new UTC timestamp when the message should sent. Mandrill can't time travel, so if you specify a time in past the message will be sent immediately

## Response

### 200

Success

- `any`

## Errors

### 401 Unauthorized Error

Invalid or missing API key.

- `status` (string, required) — Status of the response, typically "error"
- `code` (enum, required) — Numeric error code
  - Allowed values: `401`
- `name` (enum, required) — Machine-friendly error name
  - Allowed values: `Invalid_Key`
- `message` (string, required) — Human-readable error message

### 404 Not Found Error

Message not found

- `status` (string, required) — Status of the response, typically "error"
- `code` (integer, required) — Numeric error code
- `name` (string, required) — Machine-friendly error name
- `message` (string, required) — Human-readable error message

### 500 Internal Server Error

An unexpected internal server error occurred.

- `status` (string, required) — Status of the response, typically "error"
- `code` (integer, required) — Numeric error code
- `name` (string, required) — Machine-friendly error name
- `message` (string, required) — Human-readable error message

## Examples

**Request**

```json
{
  "key": "ONzNrsmbtNXoIKyfPmjnig",
  "id": "I_dtFt2ZNPW5QD9-FaDU1A",
  "send_at": "2020-06-01 08:15:01"
}
```

**Response**

```json
{
  "_id": "string",
  "created_at": "2025-08-29 18:47:42",
  "from_email": "string",
  "send_at": "2025-09-05 18:47:41",
  "subject": "string",
  "to": "string"
}
```

**SDK Code**

```python
import requests

url = "https://mandrillapp.com/api/1.4/messages/reschedule"

payload = {
    "key": "ONzNrsmbtNXoIKyfPmjnig",
    "id": "I_dtFt2ZNPW5QD9-FaDU1A",
    "send_at": "2020-06-01 08:15:01"
}
headers = {"Content-Type": "application/json"}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript
const url = 'https://mandrillapp.com/api/1.4/messages/reschedule';
const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: '{"key":"ONzNrsmbtNXoIKyfPmjnig","id":"I_dtFt2ZNPW5QD9-FaDU1A","send_at":"2020-06-01 08:15:01"}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://mandrillapp.com/api/1.4/messages/reschedule"

	payload := strings.NewReader("{\n  \"key\": \"ONzNrsmbtNXoIKyfPmjnig\",\n  \"id\": \"I_dtFt2ZNPW5QD9-FaDU1A\",\n  \"send_at\": \"2020-06-01 08:15:01\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://mandrillapp.com/api/1.4/messages/reschedule")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"key\": \"ONzNrsmbtNXoIKyfPmjnig\",\n  \"id\": \"I_dtFt2ZNPW5QD9-FaDU1A\",\n  \"send_at\": \"2020-06-01 08:15:01\"\n}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://mandrillapp.com/api/1.4/messages/reschedule")
  .header("Content-Type", "application/json")
  .body("{\n  \"key\": \"ONzNrsmbtNXoIKyfPmjnig\",\n  \"id\": \"I_dtFt2ZNPW5QD9-FaDU1A\",\n  \"send_at\": \"2020-06-01 08:15:01\"\n}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://mandrillapp.com/api/1.4/messages/reschedule', [
  'body' => '{
  "key": "ONzNrsmbtNXoIKyfPmjnig",
  "id": "I_dtFt2ZNPW5QD9-FaDU1A",
  "send_at": "2020-06-01 08:15:01"
}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://mandrillapp.com/api/1.4/messages/reschedule");
var request = new RestRequest(Method.POST);
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"key\": \"ONzNrsmbtNXoIKyfPmjnig\",\n  \"id\": \"I_dtFt2ZNPW5QD9-FaDU1A\",\n  \"send_at\": \"2020-06-01 08:15:01\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = ["Content-Type": "application/json"]
let parameters = [
  "key": "ONzNrsmbtNXoIKyfPmjnig",
  "id": "I_dtFt2ZNPW5QD9-FaDU1A",
  "send_at": "2020-06-01 08:15:01"
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://mandrillapp.com/api/1.4/messages/reschedule")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```