Creating an EML file programmatically is essential when you need to archive emails, integrate with legacy systems, or automate notifications. Aspose.3D Cloud SDK for Node.js provides a straightforward library that handles the heavy lifting, letting you focus on business logic. In this tutorial you will learn how to create EML in Node.js, see a complete working example, explore equivalent cURL commands, and discover best practices for reliable email export.

How to Create EML in Node.js - Step by Step

  1. Install the SDK and configure API keys: Use npm to add the package and create a Configuration object with your client credentials.

    const { Configuration } = require('@asposecloud/email');

const config = new Configuration({
    clientId: 'YOUR_CLIENT_ID',
    clientSecret: 'YOUR_CLIENT_SECRET'
});

  2. Initialize the EmailApi client: Pass the configuration to the EmailApi constructor.

    const { EmailApi } = require('@asposecloud/email');
const emailApi = new EmailApi(config);

    For more details, see the EmailApi reference.

  3. Create an EmailDto with sender, recipient, subject, body, and attachment: The DTO holds all email components.

    const { EmailDto, MailAddress } = require('@asposecloud/email');

const email = new EmailDto({
    from: new MailAddress({ address: 'sender@example.com', displayName: 'Sender Name' }),
    to: [new MailAddress({ address: 'recipient@example.com', displayName: 'Recipient Name' })],
    subject: 'Test Email generated via Aspose.Email Cloud SDK',
    body: 'Hello,\n\nThis is a test email created with Aspose.Email Cloud SDK for Node.js.\n\nBest regards,\nNode.js',
    isBodyHtml: false,
    attachments: [{
        name: 'sample.txt',
        content: Buffer.from('Sample attachment content').toString('base64')
    }]
});

  4. Generate the EML file: Call create with the format 'Eml'. The method returns a binary buffer.

    const emlBuffer = await emailApi.create(email, 'Eml');

  5. Write the buffer to disk: Use Node’s fs module to save the file.

    const fs = require('fs');
const path = require('path');

const outputFile = path.resolve(__dirname, 'output.eml');
fs.writeFileSync(outputFile, emlBuffer);
console.log(`EML file successfully created at: ${outputFile}`);

Complete Code Example: Create EML File with Node.js

The following code demonstrates the entire workflow from configuration to file creation.

const fs = require('fs');
const path = require('path');
const {
    EmailApi,
    EmailDto,
    MailAddress,
    Configuration
} = require('@asposecloud/email');

// -----------------------------------------------------
// 1. Install the SDK and configure API keys
// -----------------------------------------------------
const clientId = 'YOUR_CLIENT_ID';
const clientSecret = 'YOUR_CLIENT_SECRET';

const config = new Configuration({
    clientId: clientId,
    clientSecret: clientSecret,
    // baseUrl is optional; default is https://api.aspose.cloud
});

const emailApi = new EmailApi(config);

// -----------------------------------------------------
// 2. Initialize Email object and set properties
// -----------------------------------------------------
const email = new EmailDto({
    from: new MailAddress({
        address: 'sender@example.com',
        displayName: 'Sender Name'
    }),
    to: [
        new MailAddress({
            address: 'recipient@example.com',
            displayName: 'Recipient Name'
        })
    ],
    subject: 'Test Email generated via Aspose.Email Cloud SDK',
    body: 'Hello,\n\nThis is a test email created with Aspose.Email Cloud SDK for Node.js.\n\nBest regards,\nNode.js',
    isBodyHtml: false,
    // Optional: add a simple text attachment
    attachments: [
        {
            name: 'sample.txt',
            // Content must be Base64‑encoded
            content: Buffer.from('Sample attachment content').toString('base64')
        }
    ]
});

// -----------------------------------------------------
// 3. Generate EML file with Node.js
// -----------------------------------------------------
(async () => {
    try {
        // 'Eml' tells the service to return the message in .eml format
        const emlBuffer = await emailApi.create(email, 'Eml');

        // Write the binary buffer to a file
        const outputFile = path.resolve(__dirname, 'output.eml');
        fs.writeFileSync(outputFile, emlBuffer);
        console.log(`EML file successfully created at: ${outputFile}`);
    } catch (error) {
        console.error('Failed to create EML:', error);
    }
})();

Note: This code example demonstrates the core functionality. Before using it in your project, make sure to update any file paths and configuration values to match your actual environment, verify that all required dependencies are properly installed, and test thoroughly in your development environment. If you encounter any issues, please refer to the official documentation or reach out to the support team for assistance.

Generate EML via REST API with cURL

Below are the cURL commands that perform the same operation through the REST API.

  1. Obtain an access token

    curl -X POST "https://api.aspose.cloud/connect/token" \
     -H "Content-Type: application/x-www-form-urlencoded" \
     -d "grant_type=client_credentials&client_id=YOUR_CLIENT_ID&client_secret=YOUR_CLIENT_SECRET"

  2. Create the email JSON payload (save as email.json)

    {
  "from": { "address": "sender@example.com", "displayName": "Sender Name" },
  "to": [{ "address": "recipient@example.com", "displayName": "Recipient Name" }],
  "subject": "Test Email generated via Aspose.Email Cloud SDK",
  "body": "Hello,\n\nThis is a test email created with Aspose.Email Cloud SDK for Node.js.\n\nBest regards,\nNode.js",
  "isBodyHtml": false,
  "attachments": [
    {
      "name": "sample.txt",
      "content": "U2FtcGxlIGF0dGFjaG1lbnQgY29udGVudA=="
    }
  ]
}

  3. Request EML generation

    curl -X POST "https://api.aspose.cloud/email/create?format=Eml" \
     -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \
     -H "Content-Type: application/json" \
     -d @email.json --output output.eml

These commands let you generate an EML file without writing any Node.js code. For more details, see the official API documentation.

Prerequisites and Setup for Aspose.3D Cloud SDK

To start using the SDK, you need Node.js (v12 or later) and an Aspose Cloud account.

npm install aspose3dcloud

You can also download the package directly from the release page. After installation, create a free Aspose Cloud account, obtain your clientId and clientSecret, and keep them secure.

Fine-Tuning Email Generation Options

The SDK exposes several properties you can adjust:

  • isBodyHtml - Set to true if your email body contains HTML markup.
  • attachments - Add multiple objects to the attachments array; each must include a name and Base64‑encoded content.
  • customHeaders - Although not shown in the sample, you can add a customHeaders map to include additional MIME headers.

Refer to the EmailDto class reference for a full list of configurable fields.

Best Practices for EML Generation

  • Validate email addresses before sending them to the API to avoid runtime errors.
  • Base64‑encode attachment content to ensure binary data is transmitted correctly.
  • Reuse the Configuration object across multiple API calls to reduce overhead.
  • Handle errors gracefully by wrapping the create call in a try/catch block and logging the response.
  • Store generated EML files securely, especially if they contain sensitive information.

Conclusion

Creating EML in Node.js becomes a simple, repeatable process with the Aspose.3D Cloud SDK for Node.js. By following the steps, code example, and best practices outlined above, you can reliably export emails to the EML format for archiving, compliance, or downstream processing. Remember to secure your API credentials and obtain a proper license for production use; you can explore pricing options or request a temporary license at the temporary license page. Happy coding!

FAQs

How do I create EML in Node.js using Aspose.3D Cloud SDK?
Use the EmailApi class to build an EmailDto, then call create with the 'Eml' format. The complete example in this article shows the exact code.

What options can I customize when creating an EML file?
You can toggle isBodyHtml, add multiple attachments, and define custom MIME headers. See the Configuration / Options section for details.

Is a license required for production use?
A valid license is required for production deployments. Obtain a temporary license from the temporary license page or purchase a full license through the Aspose store.

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