Send Email

Send a single transactional email. Use Batch to send up to 100 different emails in one API call.

POST/v1/send

Bearer Token

Bearer

Base URL

Request Body

curl -X POST 'https://api.sendbound.com/v1/send' \
  -H 'Authorization: Bearer <your-token>' \
  -H 'Content-Type: application/json' \
  -d '{
"to": "jane@example.com",
"from": "hello@yourdomain.com",
"subject": "Welcome to Acme",
"body": "<h1>Welcome, {{name}}!</h1><p>Thanks for signing up.</p>",
"data": { "name": "Jane" }
}'

Request body

Field	Type	Required	Description
`to`	string \| object \| array	Yes	Recipient(s). A single email string, a `{name, email}` object, or an array of either.
`from`	string \| object	Yes	Sender — must be a verified domain. A plain email string or a `{name, email}` object.
`subject`	string	Yes*	Email subject line. Required unless `template` is set.
`body`	string	Yes*	HTML email body. Supports `{{variable}}` placeholders. Required unless `template` is set.
`template`	string	No	ID of a saved template to use instead of `subject`/`body`.
`data`	object	No	Variables merged into `{{placeholder}}` slots in `body` or the template.
`reply`	string	No	Reply-to email address.
`headers`	object	No	Custom email headers as key/value pairs.
`attachments`	array	No	Files to attach — see below.
`subscribed`	boolean	No	Set `true` to subscribe the contact, `false` to mark them unsubscribed. Default: preserves existing state (new contacts default to unsubscribed).

Attachment object

Field	Type	Description
`filename`	string	File name shown in the email client
`content`	string	Base64-encoded file content
`contentType`	string	MIME type, e.g. `application/pdf`

Response

{
  "success": true,
  "data": {
    "emails": [
      {
        "contact": { "id": "con_01HV3K...", "email": "jane@example.com" },
        "email": "3f2a91b0-..."
      }
    ],
    "timestamp": "2026-01-15T10:30:00.000Z"
  }
}

The email field in each result is the email record ID. Pass it to GET /emails/:id to retrieve delivery status.

Send to multiple recipients

Pass to as an array to send the same email to multiple addresses in one call. Each recipient gets their own email record:

{
  "to": [
    "alice@example.com",
    { "name": "Bob Smith", "email": "bob@example.com" }
  ],
  "from": "hello@yourdomain.com",
  "subject": "Team update",
  "body": "<p>Hi {{name}}, here is your update.</p>",
  "data": { "update": "Q3 results are in" }
}

Use a template

{
  "to": "jane@example.com",
  "from": "hello@yourdomain.com",
  "template": "tmpl_01HV3K...",
  "data": { "name": "Jane", "plan": "Pro" }
}

Error codes

Code	Description
`VALIDATION_ERROR`	Missing required field or malformed body
`DOMAIN_NOT_VERIFIED`	`from` domain has not been verified
`NOT_FOUND`	Template ID not found or not owned by your project
`RATE_LIMIT_EXCEEDED`	Too many requests — back off and retry