Send Batch Emails

Send multiple emails in a single request

Send

Send a batch of emails using the default context.

func (s *BatchSvcImpl) Send(params []*SendEmailRequest) (*BatchEmailResponse, error)

Parameters

params · []*SendEmailRequest · required

Array of email requests to send in batch. Each request should follow the same structure as a single email send request.

Returns

Returns a *BatchEmailResponse containing the results of the batch send operation.

Example

emails := []*resend.SendEmailRequest{
  {
    From:    "[e-mail]",
    To:      []string{"[e-mail]"},
    Subject: "Welcome User 1",
    Html:    "<p>Welcome to our service!</p>",
  },
  {
    From:    "[e-mail]",
    To:      []string{"[e-mail]"},
    Subject: "Welcome User 2",
    Html:    "<p>Welcome to our service!</p>",
  },
}

response, err := client.Batch.Send(emails)
if err != nil {
  panic(err)
}

---

SendWithContext

Send a batch of emails with a custom context.

func (s *BatchSvcImpl) SendWithContext(ctx context.Context, params []*SendEmailRequest) (*BatchEmailResponse, error)

Parameters

ctx · context.Context · required

Context for the request, useful for timeouts and cancellation.

params · []*SendEmailRequest · required

Array of email requests to send in batch.

Returns

Returns a *BatchEmailResponse containing the results of the batch send operation.

Example

ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()

emails := []*resend.SendEmailRequest{
  {
    From:    "[e-mail]",
    To:      []string{"[e-mail]"},
    Subject: "Welcome User 1",
    Html:    "<p>Welcome to our service!</p>",
  },
}

response, err := client.Batch.SendWithContext(ctx, emails)
if err != nil {
  panic(err)
}

---

SendWithOptions

Send a batch of emails with custom context and options.

func (s *BatchSvcImpl) SendWithOptions(ctx context.Context, params []*SendEmailRequest, options *BatchSendEmailOptions) (*BatchEmailResponse, error)

Parameters

ctx · context.Context · required

Context for the request, useful for timeouts and cancellation.

params · []*SendEmailRequest · required

Array of email requests to send in batch.

options · *BatchSendEmailOptions

Additional options for the batch send operation.

Returns

Returns a *BatchEmailResponse containing the results of the batch send operation.

Example

options := &resend.BatchSendEmailOptions{
  IdempotencyKey:  "unique-key-123",
  BatchValidation: resend.BatchValidationPermissive,
}

emails := []*resend.SendEmailRequest{
  {
    From:    "[e-mail]",
    To:      []string{"[e-mail]"},
    Subject: "Welcome",
    Html:    "<p>Welcome!</p>",
  },
}

response, err := client.Batch.SendWithOptions(context.Background(), emails, options)
if err != nil {
  panic(err)
}

---

Types

BatchSendEmailOptions

Additional options for batch email sending.

type BatchSendEmailOptions struct {
  IdempotencyKey  string              `json:"idempotency_key,omitempty"`
  BatchValidation BatchValidationMode `json:"-"`
}

IdempotencyKey · string

Unique key to ensure idempotent requests. Prevents duplicate sends if the same key is used.

BatchValidation · BatchValidationMode

Controls the validation behavior for batch emails. Can be BatchValidationStrict (default) or BatchValidationPermissive.

• BatchValidationStrict: Only sends the batch if all emails are valid
• BatchValidationPermissive: Processes all emails, allowing partial success

BatchValidationMode

Validation mode constants for batch email sending.

type BatchValidationMode string

const (
  BatchValidationStrict     BatchValidationMode = "strict"
  BatchValidationPermissive BatchValidationMode = "permissive"
)

BatchValidationStrict · BatchValidationMode

Only sends the batch if all emails are valid. This is the default mode.

BatchValidationPermissive · BatchValidationMode

Processes all emails, allowing partial success. Failed emails will be listed in the Errors field of the response.

BatchEmailResponse

Response from a batch email send operation.

type BatchEmailResponse struct {
  Data   []SendEmailResponse `json:"data"`
  Errors []BatchError        `json:"errors,omitempty"`
}

Data · []SendEmailResponse

Array of successful email send responses, each containing the email ID.

Errors · []BatchError

Array of errors for specific emails in the batch when using permissive validation mode.

BatchError

Represents an error for a specific email in a batch request.

type BatchError struct {
  Index   int    `json:"index"`
  Message string `json:"message"`
}

Index · int

The index of the failed email in the original request array.

Message · string

Error message describing why the email failed.