<form action="<?php echo base_url() . "welcome/forgotpassword" ?>" method="POST">

            <div class="form-group has-feedback">
                    <input type="email" class="form-control" placeholder="Email" name="user_email" />
                    <span class="glyphicon glyphicon-envelope form-control-feedback"></span>
             </div>
              <div class="row">
              <div class="col-xs-4">
                     <input type="submit"  class="btn btn-primary btn-block btn-flat"  value="Send">

              </div>
             </div>
    </form>

public function forgotpassword(){

    $email = $this->input->post('user_email');
    $findemail = $this->main_model->ForgotPassword($email);
    $this->load->view('forgotpassword');
    if ($findemail) {
        $this->main_model->sendpassword($findemail);
    } else {

          $this->session->set_flashdata('msg', 'Email not found!');

    }
}

public function sendpassword($data) {
    $email = $data['user_email'];
    print_r($data);
    $query1 = $this->db->query("SELECT *  from user_registration where user_email = '" . $email . "'");
    $row = $query1->result_array();


    if ($query1->num_rows() > 0) {

        $passwordplain = "";
        $passwordplain = rand(999999999, 9999999999);
        $newpass['user_password'] = md5($passwordplain);
        $this->db->where('user_email', $email);
        $this->db->update('user_registration', $newpass);
        $mail_message = 'Dear ' . $row[0]['full_name'] . ',' . "rn";
        $mail_message .= 'Thanks for contacting regarding to forgot password,<br> Your <b>Password</b> is <b>' . $passwordplain . '</b>' . "rn";
        $mail_message .= '<br>Please Update your password.';
        $mail_message .= '<br>Thanks & Regards';
        $mail_message .= '<br>Your company name';
        require FCPATH . 'assets/PHPMailer/PHPMailerAutoload.php';
        $mail = new PHPMailer;
        $mail->isSMTP();
        $mail->SMTPSecure = "tls";
        $mail->Debugoutput = 'html';
        $mail->Host = "ssl://smtp.googlemail.com";
        $mail->Port = 465;
        $mail->SMTPAuth = true;
        $mail->Username = "xxxxxxxxx@gmail.com";
        $mail->Password = "xxxxxxxx";
        $mail->setFrom('xxxxxxx@gmail.com', 'admin');
        $mail->IsHTML(true);
        $mail->addAddress('user_email', $email);
        $mail->Subject = 'OTP from company';
        $mail->Body = $mail_message;
        $mail->AltBody = $mail_message;

        if (!$mail->send()) {


            $this->session->set_flashdata('msg', 'Failed to send password, please try again!');
        } else {

            echo $this->email->print_debugger();
            $this->session->set_flashdata('msg', 'Password sent to your email!');
        }

    }
}

genererate_new_pass();

update_pass()

email_new_pass()

// all functions will return an error at each stage or not.

$this->load->database();


// load the email class
$this->load->library('email');

// mail variables
$this->email->from('your@example.com', 'Your Name');
$this->email->to('someone@example.com');
$this->email->cc('another@another-example.com');
$this->email->bcc('them@their-example.com');

$this->email->subject('Email Test');
$this->email->message('Testing the email class.');

// send the email
$this->email->send();