> ## 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. # Batch Sending > Send up to 100 emails in a single API call. Batch sending allows you to send multiple emails at once (up to 100) instead of making individual API requests for each email. ## When to use batch sending Use batch sending when you need to: * Send multiple transactional emails (e.g., order confirmations and notifications) * Trigger emails to different recipients with unique content * Reduce the number of API calls to improve performance > [!NOTE] > > For marketing campaigns, [use our no-code editor, > Broadcasts](/docs/dashboard/broadcasts/introduction), instead. ## Send batch emails You can send up to 100 emails in a single API call using the batch endpoint. Each email in the batch can have different recipients, subjects, and content. ```ts Node.js theme={"theme":{"light":"github-light","dark":"vesper"}} import { Resend } from 'resend'; const resend = new Resend('re_xxxxxxxxx'); const { data, error } = await resend.batch.send([ { from: 'Acme ', to: ['delivered@resend.dev'], subject: 'Welcome to Acme', html: '

Thanks for signing up!

', }, { from: 'Acme ', to: ['delivered@resend.dev'], subject: 'Order Confirmation', html: '

Your order has been confirmed.

', }, ]); console.log(data); ``` ```php PHP theme={"theme":{"light":"github-light","dark":"vesper"}} $resend = Resend::client('re_xxxxxxxxx'); $resend->batch->send([ [ 'from' => 'Acme ', 'to' => ['delivered@resend.dev'], 'subject' => 'Welcome to Acme', 'html' => '

Thanks for signing up!

', ], [ 'from' => 'Acme ', 'to' => ['delivered@resend.dev'], 'subject' => 'Order Confirmation', 'html' => '

Your order has been confirmed.

', ] ]); ``` ```py Python theme={"theme":{"light":"github-light","dark":"vesper"}} import resend from typing import List resend.api_key = "re_xxxxxxxxx" params: List[resend.Emails.SendParams] = [ { "from": "Acme ", "to": ["delivered@resend.dev"], "subject": "Welcome to Acme", "html": "

Thanks for signing up!

", }, { "from": "Acme ", "to": ["delivered@resend.dev"], "subject": "Order Confirmation", "html": "

Your order has been confirmed.

", } ] resend.Batch.send(params) ``` ```rb Ruby theme={"theme":{"light":"github-light","dark":"vesper"}} require "resend" Resend.api_key = 're_xxxxxxxxx' params = [ { "from": "Acme ", "to": ["delivered@resend.dev"], "subject": "Welcome to Acme", "html": "

Thanks for signing up!

", }, { "from": "Acme ", "to": ["delivered@resend.dev"], "subject": "Order Confirmation", "html": "

Your order has been confirmed.

", } ] Resend::Batch.send(params) ``` ```go Go theme={"theme":{"light":"github-light","dark":"vesper"}} 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 ", To: []string{"delivered@resend.dev"}, Subject: "Welcome to Acme", Html: "

Thanks for signing up!

", }, { From: "Acme ", To: []string{"delivered@resend.dev"}, Subject: "Order Confirmation", Html: "

Your order has been confirmed.

", }, } sent, err := client.Batch.SendWithContext(ctx, batchEmails) if err != nil { panic(err) } fmt.Println(sent.Data) } ``` ```rust Rust theme={"theme":{"light":"github-light","dark":"vesper"}} 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 ", vec!["delivered@resend.dev"], "Welcome to Acme", ) .with_html("

Thanks for signing up!

"), CreateEmailBaseOptions::new( "Acme ", vec!["delivered@resend.dev"], "Order Confirmation", ) .with_html("

Your order has been confirmed.

"), ]; let _emails = resend.batch.send(emails).await?; Ok(()) } ``` ```java Java theme={"theme":{"light":"github-light","dark":"vesper"}} import com.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 ") .to("delivered@resend.dev") .subject("Welcome to Acme") .html("

Thanks for signing up!

") .build(); CreateEmailOptions secondEmail = CreateEmailOptions.builder() .from("Acme ") .to("delivered@resend.dev") .subject("Order Confirmation") .html("

Your order has been confirmed.

") .build(); CreateBatchEmailsResponse data = resend.batch().send( Arrays.asList(firstEmail, secondEmail) ); } } ``` ```csharp .NET theme={"theme":{"light":"github-light","dark":"vesper"}} using Resend; IResend resend = ResendClient.Create("re_xxxxxxxxx"); var mail1 = new EmailMessage() { From = "Acme ", To = "delivered@resend.dev", Subject = "Welcome to Acme", HtmlBody = "

Thanks for signing up!

", }; var mail2 = new EmailMessage() { From = "Acme ", To = "delivered@resend.dev", Subject = "Order Confirmation", HtmlBody = "

Your order has been confirmed.

", }; var resp = await resend.EmailBatchAsync([mail1, mail2]); Console.WriteLine("Nr Emails={0}", resp.Content.Count); ``` ```bash cURL theme={"theme":{"light":"github-light","dark":"vesper"}} curl -X POST 'https://api.resend.com/emails/batch' \ -H 'Authorization: Bearer re_xxxxxxxxx' \ -H 'Content-Type: application/json' \ -d $'[ { "from": "Acme ", "to": ["delivered@resend.dev"], "subject": "Welcome to Acme", "html": "

Thanks for signing up!

" }, { "from": "Acme ", "to": ["delivered@resend.dev"], "subject": "Order Confirmation", "html": "

Your order has been confirmed.

" } ]' ``` ```bash CLI theme={"theme":{"light":"github-light","dark":"vesper"}} resend emails batch --file ./path/to/emails.json ``` ## Response format The batch endpoint returns an array of email IDs for successfully created emails. 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. ```json theme={"theme":{"light":"github-light","dark":"vesper"}} { "data": [ { "id": "ae2014de-c168-4c61-8267-70d2662a1ce1" }, { "id": "faccb7a5-8a28-4e9a-ac64-8da1cc3bc1cb" } ] } ``` If the request fails, the response will include an `error` object with a `message` property. You can find more information about the error in the [Errors](/docs/api-reference/errors) section of the API Reference. ## Limitations When using batch sending, keep in mind: * Maximum of **100 emails** per batch request * The `attachments` field is not supported yet * Each email in the batch is processed independently * The request will fail and return an error if any email in your payload is invalid (for example, required fields are missing or fields contain invalid data). ## View batch emails All emails sent via the batch endpoint appear in the [Emails page](https://resend.com/emails) of your dashboard along with individually sent emails. Each email will have a `queued` status initially before being processed. ## API Reference For complete API documentation, see the [Send Batch Emails API reference](/docs/api-reference/emails/send-batch-emails).