(Node.js) Mark IMAP Email as Read/Unread (Seen/Unseen)

Demonstrates how to mark emails as read or unread.

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-mac-universal');
}

function chilkatExample() {

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

    var imap = new chilkat.Imap();

    // Connect to an IMAP server.
    // Use TLS
    imap.Ssl = true;
    imap.Port = 993;
    var success = imap.Connect("imap.someMailServer.com");
    if (success !== true) {
        console.log(imap.LastErrorText);
        return;
    }

    // Login
    success = imap.Login("myLogin","myPassword");
    if (success !== true) {
        console.log(imap.LastErrorText);
        return;
    }

    // Select an IMAP mailbox
    success = imap.SelectMailbox("Inbox");
    if (success !== true) {
        console.log(imap.LastErrorText);
        return;
    }

    // Set PeekMode so that downloaded messages are not
    // automatically marked as seen.
    imap.PeekMode = true;

    // The NumMessages property contains the number of messages 
    // in the currently selected mailbox.
    var numMsgs = imap.NumMessages;
    if (numMsgs == 0) {
        return;
    }

    var i;
    for (i = 1; i <= numMsgs; i++) {
        // Download each email by sequence number (not UID)
        // email: Email
        var email;
        email = imap.FetchSingle(i,false);
        if (imap.LastMethodSuccess == false) {
            console.log(imap.LastErrorText);
            return;
        }

        // If desired, mark the email as SEEN.  There are two
        // ways to do it:

        // 1) Set the flag directly by using the sequence number
        // Indicate that we are passing a sequence number and
        // not a UID:
        var bIsUid = false;
        // Set the SEEN flag = 1 to mark the email as SEEN,
        // or set it to 0 to mark it as not-seen.
        success = imap.SetFlag(i,bIsUid,"SEEN",1);
        if (success !== true) {
            console.log(imap.LastErrorText);
            return;
        }

        // 2) Alternatively, we can use the email object.
        // When an email is downloaded from the IMAP server
        // Chilkat will add a "ckx-imap-uid" header to the email.
        // This makes it possible to know the UID associated with
        // the email.  (This is not the sequence number, which may change
        // from session to session, but the UID which does not change.
        // The SetMailFlag method is identical to SetFlag, except
        // it gets the UID from the ckx-imap-uid header.
        // For example:
        success = imap.SetMailFlag(email,"SEEN",1);
        if (success !== true) {
            console.log(imap.LastErrorText);
            return;
        }

    }

    // Disconnect from the IMAP server.
    success = imap.Disconnect();

}

chilkatExample();