(Node.js) Rename Email Attachments After Adding

Demonstrates how to rename email attachments after adding but before sending.

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.

    var mailman = new chilkat.MailMan();

    mailman.SmtpHost = "smtp.my-mail-server.com";
    mailman.SmtpUsername = "MY_SMTP_USERNAME";
    mailman.SmtpPassword = "MY_SMTP_PASSWORD";
    mailman.SmtpSsl = true;
    mailman.SmtpPort = 465;

    var email = new chilkat.Email();

    email.Subject = "This is a test";
    email.Body = "This is a test";
    email.From = "Chilkat Support <support@chilkatsoft.com>";
    var success = email.AddTo("Chilkat Admin","admin@chilkatsoft.com");
    // To add more recipients, call AddTo, AddCC, or AddBcc once per recipient.

    // Add some attachments.
    // The AddFileAttachment method returns the value of the content-type it chose for the attachment.
    var contentType = email.AddFileAttachment("qa_data/jpg/starfish.jpg");
    if (email.LastMethodSuccess !== true) {
        console.log(email.LastErrorText);
        return;
    }

    contentType = email.AddFileAttachment("qa_data/pdf/fishing.pdf");
    if (email.LastMethodSuccess !== true) {
        console.log(email.LastErrorText);
        return;
    }

    // If we save the email to a .eml, we can examine in a text editor.
    success = email.SaveEml("qa_output/e1.eml");
    if (success == false) {
        console.log(email.LastErrorText);
        console.log("Failed to save .eml");
        return;
    }

    // We see the following in the e1.eml
    // Notice that Chilkat replaced the full path with just the filename.
    // The full local path is not part of the email that gets sent..

    // ...
    // --------------020807050607070004010609
    // Content-Type: image/jpeg; name="starfish.jpg"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="starfish.jpg"
    // 
    // ...
    // --------------020807050607070004010609
    // Content-Type: application/pdf; name="fishing.pdf"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="fishing.pdf"
    // ...

    // Before sending, each filename can be changed within the email object.
    // For example:
    success = email.SetAttachmentFilename(0,"orange_starfish.jpg");
    success = email.SetAttachmentFilename(1,"tuna_fishing.pdf");

    // Look at the new MIME source of the email in a  text editor...
    success = email.SaveEml("qa_output/e2.eml");
    if (success == false) {
        console.log(email.LastErrorText);
        console.log("Failed to save .eml");
        return;
    }

    // You'll see this:

    // ...
    // --------------020807050607070004010609
    // Content-Type: image/jpeg; name="orange_starfish.jpg"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="orange_starfish.jpg"
    // 
    // ...
    // --------------020807050607070004010609
    // Content-Type: application/pdf; name="tuna_fishing.pdf"
    // Content-Transfer-Encoding: base64
    // Content-Disposition: attachment; filename="tuna_fishing.pdf"
    // ...

    // Send the email with the updated filenames..
    success = mailman.SendEmail(email);
    if (success !== true) {
        console.log(mailman.LastErrorText);
        return;
    }

    success = mailman.CloseSmtpConnection();
    if (success !== true) {
        console.log("Connection to SMTP server not closed cleanly.");
    }

    console.log("Mail with attachments sent!");

}

chilkatExample();