(Node.js) Copy Email from one IMAP Account to Another

Demonstrates how to copy the email in a mailbox from one account to another.

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() {

    var imapSrc = new chilkat.Imap();

    // This example assumes Chilkat Imap to have been previously unlocked.
    // See Unlock Imap for sample code.

    // Connect to our source IMAP server.
    imapSrc.Ssl = true;
    imapSrc.Port = 993;
    var success = imapSrc.Connect("MY-IMAP-DOMAIN");
    if (success !== true) {
        console.log(imapSrc.LastErrorText);
        return;
    }

    // Login to the source IMAP server
    success = imapSrc.Login("MY-IMAP-LOGIN","MY-IMAP-PASSWORD");
    if (success !== true) {
        console.log(imapSrc.LastErrorText);
        return;
    }

    var imapDest = new chilkat.Imap();

    // Connect to our destination IMAP server.
    imapDest.Ssl = true;
    imapDest.Port = 993;
    success = imapDest.Connect("MY-IMAP-DOMAIN2");
    if (success !== true) {
        console.log(imapDest.LastErrorText);
        return;
    }

    // Login to the destination IMAP server
    success = imapDest.Login("MY-IMAP-LOGIN2","MY-IMAP-PASSWORD2");
    if (success !== true) {
        console.log(imapDest.LastErrorText);
        return;
    }

    // Select a source IMAP mailbox on the source IMAP server
    success = imapSrc.SelectMailbox("Inbox");
    if (success !== true) {
        console.log(imapSrc.LastErrorText);
        return;
    }

    var fetchUids = true;

    // Get the set of UIDs for all emails on the source server.
    // mset: MessageSet
    var mset = imapSrc.Search("ALL",fetchUids);
    if (imapSrc.LastMethodSuccess !== true) {
        console.log(imapSrc.LastErrorText);
        return;
    }

    // Load the complete set of UIDs that were previously copied.
    // We dont' want to copy any of these to the destination.
    var fac = new chilkat.FileAccess();
    var msetAlreadyCopied = new chilkat.MessageSet();
    var strMsgSet = fac.ReadEntireTextFile("qa_cache/saAlreadyLoaded.txt","utf-8");
    if (fac.LastMethodSuccess == true) {
        msetAlreadyCopied.FromCompactString(strMsgSet);
    }

    var numUids = mset.Count;
    var sbFlags = new chilkat.StringBuilder();

    var i = 0;
    while (i < numUids) {

        // If this UID was not already copied...
        var uid = mset.GetId(i);
        if (!msetAlreadyCopied.ContainsId(uid)) {

            console.log("copying " + uid + "...");

            // Get the flags.
            var flags = imapSrc.FetchFlags(uid,true);
            if (imapSrc.LastMethodSuccess == false) {
                console.log(imapSrc.LastErrorText);
                return;
            }

            sbFlags.SetString(flags);

            // Get the MIME of this email from the source.
            var mimeStr = imapSrc.FetchSingleAsMime(uid,true);
            if (imapSrc.LastMethodSuccess == false) {
                console.log(imapSrc.LastErrorText);
                return;
            }

            var seen = sbFlags.Contains("\\Seen",false);
            var flagged = sbFlags.Contains("\\Flagged",false);
            var answered = sbFlags.Contains("\\Answered",false);
            var draft = sbFlags.Contains("\\Draft",false);

            success = imapDest.AppendMimeWithFlags("Inbox",mimeStr,seen,flagged,answered,draft);
            if (success !== true) {
                console.log(imapDest.LastErrorText);
                return;
            }

            // Update msetAlreadyCopied with the uid just copied.
            msetAlreadyCopied.InsertId(uid);

            // Save at every iteration just in case there's a failure..
            strMsgSet = msetAlreadyCopied.ToCompactString();
            fac.WriteEntireTextFile("qa_cache/saAlreadyLoaded.txt",strMsgSet,"utf-8",false);
        }

        i = i+1;
    }

    // Disconnect from the IMAP servers.
    success = imapSrc.Disconnect();
    success = imapDest.Disconnect();

}

chilkatExample();