(Node.js) Send HTML Email with Embedded Image Loaded from Memory

Demonstrates how to compose an HTML email with an embedded image where the image data is loaded directly from memory.

Install Chilkat for Node.js and Electron using npm at

Chilkat npm packages for Node.js
Chilkat npm packages for Electron
on Windows, Linux, MacOSX, and ARM

var os = require('os');
if (os.platform() == 'win32') {  
    if (os.arch() == 'ia32') {
        var chilkat = require('@chilkat/ck-node21-win-ia32');
    } else {
        var chilkat = require('@chilkat/ck-node21-win64'); 
    }
} else if (os.platform() == 'linux') {
    if (os.arch() == 'arm') {
        var chilkat = require('@chilkat/ck-node21-arm');
    } else if (os.arch() == 'x86') {
        var chilkat = require('@chilkat/ck-node21-linux32');
    } else {
        var chilkat = require('@chilkat/ck-node21-linux64');
    }
} else if (os.platform() == 'darwin') {
    if (os.arch() == 'arm64') {
        var chilkat = require('@chilkat/ck-node21-mac-m1');
    } else {
        var chilkat = require('@chilkat/ck-node21-macosx');
    }
}

function chilkatExample() {

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

    // First load image data into memory.
    // This example loads image data from a file.
    // However, your application could get the image data from any other source, such as
    // from a database.
    var fac = new chilkat.FileAccess();

    imageBytes = fac.ReadEntireFile("qa_data/jpg/starfish.jpg");

    // The mailman object is used for sending and receiving email.
    var mailman = new chilkat.MailMan();

    // Use your SMTP server hostname.  This example uses office365, but it could be any SMTP server..
    mailman.SmtpHost = "outlook.office365.com";
    mailman.SmtpPort = 587;
    mailman.StartTLS = true;

    // Set the SMTP login/password
    mailman.SmtpUsername = "OFFICE365-SMTP-LOGIN";
    mailman.SmtpPassword = "OFFICE365-SMTP-PASSWORD";

    // Create a new email object
    var email = new chilkat.Email();
    email.Subject = "HTML Email with Image Loaded from In-Memory Bytes";
    email.From = "Chilkat Support <my-office365-user@mydomain.com>";
    email.AddTo("Chilkat Support","support@chilkatsoft.com");

    var contentIdStarfish = email.AddRelatedData("starfish.jpg",imageBytes);
    if (email.LastMethodSuccess !== true) {
        console.log(email.LastErrorText);
        return;
    }

    // The src attribute for the image tag is set to the contentIdStarfish:
    var sbHtml = new chilkat.StringBuilder();
    sbHtml.Append("<html><body><p>This is an HTML email with an embedded image.</p>");
    sbHtml.Append("<p><img src=\"cid:CONTENT_ID_STARFISH\" /></p></body></html>");
    var numReplacements = sbHtml.Replace("CONTENT_ID_STARFISH",contentIdStarfish);

    email.SetHtmlBody(sbHtml.GetAsString());

    var success = mailman.SendEmail(email);
    if (success !== true) {
        console.log(mailman.LastErrorText);
    }
    else {
        console.log("Mail Sent!");
    }


}

chilkatExample();