# Send Batch Emails

POST

/

emails

/

batch

:::code-group
```typescript title="Node.js"
import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.batch.send([
  {
    from: 'Acme <onboarding@resend.dev>',
    to: ['foo@gmail.com'],
    subject: 'hello world',
    html: '<h1>it works!</h1>',
  },
  {
    from: 'Acme <onboarding@resend.dev>',
    to: ['bar@outlook.com'],
    subject: 'world hello',
    html: '<p>it works!</p>',
  },
]);
```

```php title="PHP"
$resend = Resend::client('re_xxxxxxxxx');

$resend->batch->send([
  [
    'from' => 'Acme <onboarding@resend.dev>',
    'to' => ['foo@gmail.com'],
    'subject' => 'hello world',
    'html' => '<h1>it works!</h1>',
  ],
  [
    'from' => 'Acme <onboarding@resend.dev>',
    'to' => ['bar@outlook.com'],
    'subject' => 'world hello',
    'html' => '<p>it works!</p>',
  ]
]);
```

```python title="Python"
import resend
from typing import List

resend.api_key = "re_xxxxxxxxx"

params: List[resend.Emails.SendParams] = [
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["foo@gmail.com"],
    "subject": "hello world",
    "html": "<h1>it works!</h1>",
  },
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["bar@outlook.com"],
    "subject": "world hello",
    "html": "<p>it works!</p>",
  }
]

resend.Batch.send(params)
```

```ruby title="Ruby"
require "resend"

Resend.api_key = 're_xxxxxxxxx'

params = [
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["foo@gmail.com"],
    "subject": "hello world",
    "html": "<h1>it works!</h1>",
  },
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["bar@outlook.com"],
    "subject": "world hello",
    "html": "<p>it works!</p>",
  }
]

Resend::Batch.send(params)
```

```go title="Go"
package main

import (
	"context"
	"fmt"

	"github.com/resend/resend-go/v4"
)

func main() {

  ctx := context.TODO()

  client := resend.NewClient("re_xxxxxxxxx")

  var batchEmails = []*resend.SendEmailRequest{
    {
      From:    "Acme <onboarding@resend.dev>",
      To:      []string{"foo@gmail.com"},
      Subject: "hello world",
      Html:    "<h1>it works!</h1>",
    },
    {
      From:    "Acme <onboarding@resend.dev>",
      To:      []string{"bar@outlook.com"},
      Subject: "world hello",
      Html:    "<p>it works!</p>",
    },
  }

  sent, err := client.Batch.SendWithContext(ctx, batchEmails)

  if err != nil {
    panic(err)
  }
  fmt.Println(sent.Data)
}
```

```rust title="Rust"
use resend_rs::types::CreateEmailBaseOptions;
use resend_rs::{Resend, Result};

#[tokio::main]
async fn main() -> Result<()> {
  let resend = Resend::new("re_xxxxxxxxx");

  let emails = vec![
    CreateEmailBaseOptions::new(
      "Acme <onboarding@resend.dev>",
      vec!["foo@gmail.com"],
      "hello world",
    )
    .with_html("<h1>it works!</h1>"),
    CreateEmailBaseOptions::new(
      "Acme <onboarding@resend.dev>",
      vec!["bar@outlook.com"],
      "world hello",
    )
    .with_html("<p>it works!</p>"),
  ];

  let _emails = resend.batch.send(emails).await?;

  Ok(())
}
```

```java title="Java"
import com.resend.Resend;
import com.resend.core.exception.ResendException;
import com.resend.services.batch.model.CreateBatchEmailsResponse;
import com.resend.services.emails.model.CreateEmailOptions;
import java.util.Arrays;

public class Main {
    public static void main(String[] args) throws ResendException {
        Resend resend = new Resend("re_xxxxxxxxx");

        CreateEmailOptions firstEmail = CreateEmailOptions.builder()
            .from("Acme <onboarding@resend.dev>")
            .to("foo@gmail.com")
            .subject("hello world")
            .html("<h1>it works!</h1>")
            .build();

        CreateEmailOptions secondEmail = CreateEmailOptions.builder()
            .from("Acme <onboarding@resend.dev>")
            .to("bar@outlook.com")
            .subject("world hello")
            .html("<p>it works!</p>")
            .build();

        CreateBatchEmailsResponse data = resend.batch().send(
            Arrays.asList(firstEmail, secondEmail)
        );
    }
}
```

```csharp title=".NET"
using Resend;

IResend resend = ResendClient.Create( "re_xxxxxxxxx" ); // Or from DI

var mail1 = new EmailMessage()
{
    From = "Acme <onboarding@resend.dev>",
    To = "foo@gmail.com",
    Subject = "hello world",
    HtmlBody = "<p>it works!</p>",
};

var mail2 = new EmailMessage()
{
    From = "Acme <onboarding@resend.dev>",
    To = "bar@outlook.com",
    Subject = "hello world",
    HtmlBody = "<p>it works!</p>",
};

var resp = await resend.EmailBatchAsync( [ mail1, mail2 ] );
Console.WriteLine( "Nr Emails={0}", resp.Content.Count );
```

```shellscript title="cURL"
curl -X POST 'https://api.resend.com/emails/batch' \
     -H 'Authorization: Bearer re_xxxxxxxxx' \
     -H 'Content-Type: application/json' \
     -d $'[
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["foo@gmail.com"],
    "subject": "hello world",
    "html": "<h1>it works!</h1>"
  },
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["bar@outlook.com"],
    "subject": "world hello",
    "html": "<p>it works!</p>"
  }
]'
```

```shellscript title="CLI"
resend emails batch --file ./path/to/emails.json
```
:::

:::code-group
```json title="Response"
{
  "data": [
    {
      "id": "ae2014de-c168-4c61-8267-70d2662a1ce1"
    },
    {
      "id": "faccb7a5-8a28-4e9a-ac64-8da1cc3bc1cb"
    }
  ]
}
```
:::

Instead of sending one email per HTTP request, Resend provides a batching endpoint that permits you to send up to 100 emails in a single API call.

## Body Parameters

string

required

Sender email address.To include a friendly name, pass the sender as `Name <email@example.com>`, for example `Acme <onboarding@example.dev>`.

string | string\[]

required

Recipient email address. For multiple addresses, send as an array of strings. Max 50.

string

required

Email subject.

string | string\[]

Bcc recipient email address. For multiple addresses, send as an array of strings.

string | string\[]

Cc recipient email address. For multiple addresses, send as an array of strings.

string

The HTML version of the message.

string

The plain text version of the message.

:::callout{intent="info"}
If not provided, the HTML will be used to generate a plain text version. You can opt out of this behavior by setting value to an empty string.
:::

React.ReactNode

The React component used to write the message. _Only available in the Node.js SDK._

object

Custom headers to add to the email.

array

Custom data passed in key/value pairs.[See examples](/guides/learn-dashboard-emails-tags).

:::accordion{title="Hide properties" open="true"}
string

required

The name of the email tag.It can only contain ASCII letters (a–z, A–Z), numbers (0–9), underscores (\_), or dashes (-).It can contain no more than 256 characters.

string

required

The value of the email tag.It can only contain ASCII letters (a–z, A–Z), numbers (0–9), underscores (\_), or dashes (-).It can contain no more than 256 characters.
:::

object

To send using a template, provide a `template` object with:

- `id`: the id _or_ the alias of the published template
- `variables`: an object with a key for each variable (if applicable)

:::callout{intent="info"}
If a `template` is provided, you cannot send `html`, `text`, or `react` in the payload, otherwise the API will return a validation error.When sending a template, the payload for `from`, `subject`, and `reply_to` take precedence over the template’s defaults for these fields. If the template does not provide a default value for these fields, you must provide them in the payload.
:::

string

required

The id of the published email template. Required if `template` is provided. Only published templates can be used when sending emails.

object

Template variables object with key/value pairs.

```typescript
variables: {
	CTA: 'Sign up now',
	CTA_LINK: 'https://example.com/signup'
}
```

When sending the template, the HTML will be parsed. If all the variables used in the template were provided, the email will be sent. If not, the call will throw a validation error.See the [errors reference](/guides/api-reference-errors) for more details or [learn more about templates](/guides/learn-dashboard-templates-introduction).

:::accordion{title="Hide properties" open="true"}
string

required

The key of the variable.May only contain ASCII letters (a–z, A–Z), numbers (0–9), and underscores (\_). The following variable names are reserved and cannot be used: `FIRST_NAME`, `LAST_NAME`, `EMAIL`, `UNSUBSCRIBE_URL`.It can contain no more than 50 characters.

string | number

required

The value of the variable.Observe these technical limitations:

- `string`: maximum length of 2,000 characters
- `number`: not greater than 2^53 - 1
:::

## Headers

string

Add an idempotency key to prevent duplicated emails.

- Should be **unique per API request**
- Idempotency keys expire after **24 hours**
- Have a maximum length of **256 characters**

[Learn more about idempotency keys →](/guides/learn-dashboard-emails-idempotency-keys)

## Limitations

The `attachments` field is not supported yet.

## Response format

When the request succeeds, each entry in `data` corresponds to the email at the same index in the batch payload (0-based). The first email in your request will be the first entry in `data`, and so on.

:::code-group
```typescript title="Node.js"
import { Resend } from 'resend';

const resend = new Resend('re_xxxxxxxxx');

const { data, error } = await resend.batch.send([
  {
    from: 'Acme <onboarding@resend.dev>',
    to: ['foo@gmail.com'],
    subject: 'hello world',
    html: '<h1>it works!</h1>',
  },
  {
    from: 'Acme <onboarding@resend.dev>',
    to: ['bar@outlook.com'],
    subject: 'world hello',
    html: '<p>it works!</p>',
  },
]);
```

```php title="PHP"
$resend = Resend::client('re_xxxxxxxxx');

$resend->batch->send([
  [
    'from' => 'Acme <onboarding@resend.dev>',
    'to' => ['foo@gmail.com'],
    'subject' => 'hello world',
    'html' => '<h1>it works!</h1>',
  ],
  [
    'from' => 'Acme <onboarding@resend.dev>',
    'to' => ['bar@outlook.com'],
    'subject' => 'world hello',
    'html' => '<p>it works!</p>',
  ]
]);
```

```python title="Python"
import resend
from typing import List

resend.api_key = "re_xxxxxxxxx"

params: List[resend.Emails.SendParams] = [
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["foo@gmail.com"],
    "subject": "hello world",
    "html": "<h1>it works!</h1>",
  },
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["bar@outlook.com"],
    "subject": "world hello",
    "html": "<p>it works!</p>",
  }
]

resend.Batch.send(params)
```

```ruby title="Ruby"
require "resend"

Resend.api_key = 're_xxxxxxxxx'

params = [
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["foo@gmail.com"],
    "subject": "hello world",
    "html": "<h1>it works!</h1>",
  },
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["bar@outlook.com"],
    "subject": "world hello",
    "html": "<p>it works!</p>",
  }
]

Resend::Batch.send(params)
```

```go title="Go"
package main

import (
	"context"
	"fmt"

	"github.com/resend/resend-go/v4"
)

func main() {

  ctx := context.TODO()

  client := resend.NewClient("re_xxxxxxxxx")

  var batchEmails = []*resend.SendEmailRequest{
    {
      From:    "Acme <onboarding@resend.dev>",
      To:      []string{"foo@gmail.com"},
      Subject: "hello world",
      Html:    "<h1>it works!</h1>",
    },
    {
      From:    "Acme <onboarding@resend.dev>",
      To:      []string{"bar@outlook.com"},
      Subject: "world hello",
      Html:    "<p>it works!</p>",
    },
  }

  sent, err := client.Batch.SendWithContext(ctx, batchEmails)

  if err != nil {
    panic(err)
  }
  fmt.Println(sent.Data)
}
```

```rust title="Rust"
use resend_rs::types::CreateEmailBaseOptions;
use resend_rs::{Resend, Result};

#[tokio::main]
async fn main() -> Result<()> {
  let resend = Resend::new("re_xxxxxxxxx");

  let emails = vec![
    CreateEmailBaseOptions::new(
      "Acme <onboarding@resend.dev>",
      vec!["foo@gmail.com"],
      "hello world",
    )
    .with_html("<h1>it works!</h1>"),
    CreateEmailBaseOptions::new(
      "Acme <onboarding@resend.dev>",
      vec!["bar@outlook.com"],
      "world hello",
    )
    .with_html("<p>it works!</p>"),
  ];

  let _emails = resend.batch.send(emails).await?;

  Ok(())
}
```

```java title="Java"
import com.resend.Resend;
import com.resend.core.exception.ResendException;
import com.resend.services.batch.model.CreateBatchEmailsResponse;
import com.resend.services.emails.model.CreateEmailOptions;
import java.util.Arrays;

public class Main {
    public static void main(String[] args) throws ResendException {
        Resend resend = new Resend("re_xxxxxxxxx");

        CreateEmailOptions firstEmail = CreateEmailOptions.builder()
            .from("Acme <onboarding@resend.dev>")
            .to("foo@gmail.com")
            .subject("hello world")
            .html("<h1>it works!</h1>")
            .build();

        CreateEmailOptions secondEmail = CreateEmailOptions.builder()
            .from("Acme <onboarding@resend.dev>")
            .to("bar@outlook.com")
            .subject("world hello")
            .html("<p>it works!</p>")
            .build();

        CreateBatchEmailsResponse data = resend.batch().send(
            Arrays.asList(firstEmail, secondEmail)
        );
    }
}
```

```csharp title=".NET"
using Resend;

IResend resend = ResendClient.Create( "re_xxxxxxxxx" ); // Or from DI

var mail1 = new EmailMessage()
{
    From = "Acme <onboarding@resend.dev>",
    To = "foo@gmail.com",
    Subject = "hello world",
    HtmlBody = "<p>it works!</p>",
};

var mail2 = new EmailMessage()
{
    From = "Acme <onboarding@resend.dev>",
    To = "bar@outlook.com",
    Subject = "hello world",
    HtmlBody = "<p>it works!</p>",
};

var resp = await resend.EmailBatchAsync( [ mail1, mail2 ] );
Console.WriteLine( "Nr Emails={0}", resp.Content.Count );
```

```shellscript title="cURL"
curl -X POST 'https://api.resend.com/emails/batch' \
     -H 'Authorization: Bearer re_xxxxxxxxx' \
     -H 'Content-Type: application/json' \
     -d $'[
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["foo@gmail.com"],
    "subject": "hello world",
    "html": "<h1>it works!</h1>"
  },
  {
    "from": "Acme <onboarding@resend.dev>",
    "to": ["bar@outlook.com"],
    "subject": "world hello",
    "html": "<p>it works!</p>"
  }
]'
```

```shellscript title="CLI"
resend emails batch --file ./path/to/emails.json
```
:::

```json
{
  "data": [
    {
      "id": "ae2014de-c168-4c61-8267-70d2662a1ce1"
    },
    {
      "id": "faccb7a5-8a28-4e9a-ac64-8da1cc3bc1cb"
    }
  ]
}
```

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- [Account Management](./account-management-index.md)
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