(Node.js) Send HTML Email with Image to iPhone

Demonstrates how to compose an HTML email with an embedded image that will display correctly on an iPhone. This example produces an email that looks like this on the iPhone:

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.

    // 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 = "Testing for Chilkat SMTP API...";
    email.Body = "Testing for Chilkat SMTP API...";
    email.From = "Chilkat Support <my-office365-user@mydomain.com>";
    email.AddTo("Chilkat Support","support@chilkatsoft.com");

    // For whatever reason, the iPhone's email program requires
    // images in HTML to be referenced by Content-ID.  Therefore,
    // we must add the image like this:
    var contentIdStarfish = email.AddRelatedFile("qa_data/jpg/starfish.jpg");
    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();