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Send via API

This section helps you integrate with the MX18 Email API and send your first email via a simple POST request.

Pre-requisites

To send an email using MX18’s API, ensure the following:

⚠️ Requests without a valid token or unverified sender domain will be rejected.

API endpoint

Use the following endpoint to send emails via MX18’s Mail Send API:

POST https://api.mx18.com/v1/mail/send

Authentication is handled via the `Authorization` header:

Authorization: Bearer YOUR_API_TOKEN Content-Type: application/json

Sample request payload

{
  "from": {
    "name": "Your Business Name",
    "email": "info@mails.yourdomain.com"
  },
  "replyTo": {
    "name": "MX18 Support",
    "email": "support@mx18.ai"
  },
  "to": [
    {
      "name": "Example Customer",
      "email": "user@example.com",
      "personalizationData": {
        "key1": "value",
        "key2": "value"
      }
    }
  ],
  "cc": [
    {
      "name": "Manager",
      "email": "manager@example.com"
    }
  ],
  "bcc": [
    {
      "name": "Auditor",
      "email": "auditor@example.com"
    }
  ],
  "globalPersonalizationData": {
    "key1": "value",
    "key2": "value"
  },
  "message": {
    "subject": "Test Mail - Here is a subject line",
    "content": [
      {
        "type": "text/html",
        "value": "Hello, this is HTML content. <a href=':key'>Click here</a>"
      },
      {
        "type": "text/plain",
        "value": "This is a plain text version of the email."
      }
    ],
    "attachments": [
      {
        "type": "application/pdf",
        "file_name": "invoice.pdf",
        "disposition": "attachment",
        "data": "<base64_encoded_string>"
      }
    ],
    "headers": {
      "X-Custom-Header": "CustomValue",
      "X-Mailer": "MX18 API"
    }
  }
}

Success response

{
"transactionId": "abc123xyz456",
"status": "Accepted",
"message": "Email request has been accepted for delivery."
}

Field reference

Top-level fields

Field Description
from Sender's name and email address
replyTo Optional reply address
to, cc, bcc Arrays of recipient objects
globalPersonalizationData Fallback dynamic values for template personalization

Recipient-level personalization

Field Description
personalizationData Dynamic values unique to each recipient

Message object

Field Description
subject Subject line of the email
content Array of content blocks (text/plain, text/html, etc.)
attachments List of attachment objects
headers Custom headers to include with the email
templateId Reference to a predefined template in your MX18 account

Attachment object fields

Field Description
type MIME type (e.g., application/pdf)
file_name Filename displayed to the recipient
disposition Either attachment or inline
data Base64-encoded file content

Need help?

If you encounter issues while using the API:

  • Double-check your API token and domain verification status

  • Use a valid email format for all recipients

  • Contact our support team at support@mx18.com

For next steps, explore: