(Node.js) Download POP3 Email using UIDLs

Demonstrates how to download POP3 email by first getting the complete set of UIDLs and then downloading email by calling FetchEmail for each UIDL. This is equivalent to calling CopyMail, except your application can process each email as it arrives instead of waiting for the entire bundle to be downloaded. Also, it's better protection against potential out-of-memory issues if your mailbox has a very large number of messages. There is no performance difference between fetching emails individually vs. calling CopyMail.

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.

    // The mailman object is used for receiving (POP3) 
    // and sending (SMTP) email.
    var mailman = new chilkat.MailMan();

    // Set the POP3 server's hostname
    mailman.MailHost = "pop.someMailServer.com";

    // Set the POP3 login/password.
    mailman.PopUsername = "myLogin";
    mailman.PopPassword = "myPassword";

    // sa: StringArray
    var sa = mailman.GetUidls();
    if (mailman.LastMethodSuccess !== true) {
        console.log(mailman.LastErrorText);
        return;
    }

    var i = 0;
    var n = sa.Count;

    var uidl;

    while (i < n) {

        uidl = sa.GetString(i);

        // email: Email
        var email = mailman.FetchEmail(uidl);
        if (mailman.LastMethodSuccess !== true) {
            console.log(mailman.LastErrorText);

            return;
        }

        console.log("From: " + email.From);
        console.log("Subject: " + email.Subject);

        i = i+1;
    }

    mailman.Pop3EndSession();

}

chilkatExample();