Imap with Node.js, marking Email as read

I'm using Imap with node.js, and every time i connect it, it fetch al the emails from a data i gave it, but doens't mark them as read, so the following time it re-fecth them again.

Here is my code(All the functions implemented here are called in a main.js file), what can I change to mark the e-mail I'm fetching as read?

I've tried to do like written here (how to mark unseen email as seen with node-imap in node.js) but it didn't work..

var Imap = require('imap');
var inspect = require('util').inspect;
var formatter = require('./formatter.js');

var mailError = exports.mailError = [];

var imap = new Imap({
  user: 'aaaaaaaaa@gmail.com',
  password: 'xxxxxxx',
  host: 'imap.gmail.com',
  port: 993,    //Perchè non 143, standard IMAP?
  tls: true,
  markSeen: true
});

function openInbox(cb) {
  imap.openBox('INBOX', false, cb);
}


var onBodyCb = exports.onBodyCb = function(parsedHeaders, body){
    var pos = (body.indexOf("Delivery to the following recipient failed permanently:") + 55);
    var address = body.substr(pos,50);
    var at = address.indexOf("@");
    address = address.substr(0,at+formatter.company.length+formatter.domain.length+2);
    address = address.replace(/ /g,'');
    address = address.replace(/(\r\n|\n|\r)/gm,"");
    console.log("onBodyCB:  "+address+'\n');
    mailError.push(address);    
};

var onFinishedFetching = exports.onFinishedFetching = function(){};

imap.once('ready', function() {
    var fs = require('fs'), fileStream;

    openInbox(function(err, box) {
      if (err) throw err;
      imap.search([ 'UNSEEN', ['SINCE', 'July 10, 2014'] ], function(err, results) {
        if (err) throw err;
        // a questo abbiamo la box a cui possiamo accedere
        var f = imap.fetch(results, { bodies: '' });
        f.on('message', function(msg, seqno) {
          //console.log('Message #%d', seqno);
          var prefix = '(#' + seqno + ') ';
          msg.on('body', function(stream, info) {
            console.log(prefix + 'Body');
            var buffer = '';
             stream.on('data', function(chunk) {
              buffer += chunk.toString('utf8');
            });
            //console.log(buffer);
            stream.once('end', function() {
              //console.log(prefix + 'Parsed header: %s', inspect());
              var header = Imap.parseHeader(buffer);
              exports.onBodyCb(header, buffer);
            });
          });
          //msg.once('attributes', function(attrs) {
          //  console.log(prefix + 'Attributes: %s', inspect(attrs, false, 8));
          //});
          msg.once('end', function() {
            //console.log(prefix + 'Finished');
          });
        });
        f.once('error', function(err) {
          console.log('Fetch error: ' + err);
        });
        f.once('end', function() {
          console.log('Done fetching all messages!');
          imap.end();
          exports.onFinishedFetching();
        });
      });
    });
});

imap.once('error', function(err) {
  console.log(err);
});

imap.once('end', function() {
  console.log('Connection ended');

});

exports.connect = function(){
    imap.connect();
};

EDIT:

I've changed as suggested but it still doesn't work...

var Imap = require('imap');
var inspect = require('util').inspect;
var formatter = require('./formatter.js');

var mailError = exports.mailError = [];

var imap = new Imap({
  user: 'marco.loco.recruiter@gmail.com',
  password: 'coci2014',
  host: 'imap.gmail.com',
  port: 993,    //Perchè non 143, standard IMAP?
  tls: true,
  markSeen : true,
  markRead : true
});

function openInbox(cb) {
  imap.openBox('INBOX', false, cb);
}


var onBodyCb = exports.onBodyCb = function(parsedHeaders, body){
    var pos = (body.indexOf("Delivery to the following recipient failed permanently:") + 55);
    var address = body.substr(pos,50);
    var at = address.indexOf("@");
    address = address.substr(0,at+formatter.company.length+formatter.domain.length+2);
    address = address.replace(/ /g,'');
    address = address.replace(/(\r\n|\n|\r)/gm,"");
    console.log("onBodyCB:  "+address+'\n');
    mailError.push(address);    
};

var onFinishedFetching = exports.onFinishedFetching = function(){};

imap.once('ready', function() {
    var fs = require('fs'), fileStream;

    openInbox(function(err, box) {
      if (err) throw err;
      imap.search([ 'UNSEEN', ['SINCE', 'July 10, 2014'] ], function(err, results) {
        if (err) throw err;
        // a questo abbiamo la box a cui possiamo accedere
        var f = imap.fetch(results, { bodies: '' });
        f.on('message', function(msg, seqno) {
          //console.log('Message #%d', seqno);
          var prefix = '(#' + seqno + ') ';
          msg.on('body', function(stream, info) {
            //console.log(prefix + 'Body');
            var buffer = '';
             stream.on('data', function(chunk) {
              buffer += chunk.toString('utf8');
            });
            //console.log(buffer);
            stream.once('end', function() {
              //console.log(prefix + 'Parsed header: %s', inspect());
              var header = Imap.parseHeader(buffer);
              exports.onBodyCb(header, buffer);
            });
          });
          //msg.once('attributes', function(attrs) {
          //  console.log(prefix + 'Attributes: %s', inspect(attrs, false, 8));
          //});
          msg.once('end', function() {
            //console.log(prefix + 'Finished');
          });
        });
        f.once('error', function(err) {
          console.log('Fetch error: ' + err);
        });
        f.once('end', function() {
          console.log('Done fetching all messages!');
          imap.end();
          exports.onFinishedFetching();
        });
      });
    },false);
});

imap.once('error', function(err) {
  console.log(err);
});

imap.once('end', function() {
  console.log('Connection ended');

});

exports.connect = function(){
    imap.connect();
};