(Node.js) Create Complex Email

This is an example showing how to create an email that has file attachments, contains both plain-text and HTML alternative bodies, and has embedded images within the HTML. The email is saved to a .eml file, which is a text file and can be viewed in any text editor. EML is nothing more than the MIME source of an email. In this example, you'll see that the MIME is structured in three layers of multipart content types. The outermost layer is multipart/mixed. This is typically where you'll find file attachments and attached messages. Underneath the multipart/mixed is a multipart/related envelope. Within this you'll find the "related" items -- which are the items belonging to the HTML body (images and style sheets). Underneath the multipart/related you'll find the multipart/alternative, and this contains the text/plain and text/html alternative bodies.

Install Chilkat for Node.js and Electron using npm at

Chilkat npm packages for Node.js
Chilkat npm packages for Electron
on Windows, Linux, MacOS

var os = require('os');
if (os.platform() == 'win32') {  
  var chilkat = require('@chilkat/ck-node23-win64'); 
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node23-linux-arm');
    } else if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node23-linux-arm64');
    } else {
        var chilkat = require('@chilkat/ck-node23-linux-x64');
    }
} else if (os.platform() == 'darwin') {
  var chilkat = require('@chilkat/ck-node23-darwin-universal');
}

function chilkatExample() {

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    var email = new chilkat.Email();

    // Adding attachments, HTML/plain-text bodies, etc can be done
    // in any order:

    // Add an attachment
    var contentType = email.AddFileAttachment("hamlet.zip");
    if (email.LastMethodSuccess !== true) {
        console.log(email.LastErrorText);
        return;
    }

    // Add some headers:
    email.Subject = "This is a complex email";
    var success = email.AddTo("Chilkat Support","support@chilkatsoft.com");
    email.From = "Matt <matt@chilkatsoft.com>";

    // Add a plain-text body:
    success = email.AddPlainTextAlternativeBody("This is the plain-text body");

    // Add an image that will be embedded in the HTML body.
    var contentIdDude = email.AddRelatedFile("dude.gif");
    if (email.LastMethodSuccess !== true) {
        console.log(email.LastErrorText);
        return;
    }

    // Update the CONTENT_ID_DUDE to the actual content ID when sending the email.
    success = email.SetReplacePattern("CONTENT_ID_DUDE",contentIdDude);

    // Add an HTML body:
    var html;
    html = "<html><body><b>This is the HTML body</b><br><img src=\"cid:CONTENT_ID_DUDE\"></body></html>";

    success = email.AddHtmlAlternativeBody(html);

    // Save the email as a .eml

    success = email.SaveEml("complex.eml");
    if (success !== true) {
        console.log(email.LastErrorText);
    }
    else {
        console.log("Created email!");
    }


}

chilkatExample();