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POST /api/v1/emails

Send Email

Send a transactional email to one or more recipients.

Request

Parameters

Parameter Type Required Description
from string required Sender email address. Must be from a verified domain.
to string required Recipient email address.
subject string required Email subject line.
body string optional Plain text email body.
text_body string optional Plain text body (alias for body).
html_body string optional HTML email body.
attachments array optional Array of attachment objects.

Attachment Object

Field Type Description
filename string Name of the attachment file.
io string Base64-encoded file content.
content_type string MIME type (e.g., application/pdf).

Examples

Simple email

cURL 
curl -X POST https://eml.dev/api/v1/emails \
  -H "Authorization: Token YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "hello@yourdomain.com",
    "to": "user@example.com",
    "subject": "Welcome!",
    "body": "Thanks for signing up."
  }'

HTML email

cURL 
curl -X POST https://eml.dev/api/v1/emails \
  -H "Authorization: Token YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "hello@yourdomain.com",
    "to": "user@example.com",
    "subject": "Order Confirmed",
    "text_body": "Your order #1234 has been confirmed.",
    "html_body": "<h1>Order Confirmed</h1><p>Your order #1234 has been confirmed.</p>"
  }'

Email with attachment

cURL 
curl -X POST https://eml.dev/api/v1/emails \
  -H "Authorization: Token YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "hello@yourdomain.com",
    "to": "user@example.com",
    "subject": "Your Invoice",
    "text_body": "Please find your invoice attached.",
    "attachments": [{
      "filename": "invoice.pdf",
      "io": "JVBERi0xLjQKJeLjz9...",
      "content_type": "application/pdf"
    }]
  }'

Note: Attachment content must be Base64-encoded. In most languages, you can use built-in functions like base64.b64encode() (Python) or Buffer.from().toString('base64') (Node.js).

Response

Success (200)

JSON 
{
  "id": "msg_abc123...",
  "status": "queued"
}

Error (422)

JSON 
{
  "error": "Validation failed",
  "messages": ["to is required", "subject is required"]
}
Documentation