SMTP ERROR Failed to connect to server A connection attempt failed - php

Question

I have a problem sending an email and this is the error:
Connection: opening to smtp.gmail.com:587, timeout=300, options=array()
Connection failed. Error #2: stream_socket_client(): unable to connect to smtp.gmail.com:587 (A connection attempt failed because the connected party did not respond properly after a period of time, or established connection failed because connected host has failed to respond.)
SMTP ERROR: Failed to connect to server: A connection attempt failed because the connected party did not respond properly after a period of time, or the established connection failed because the connected host failed to respond. (10060)
I've adjusted the one on https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting and it's still an error, can someone help me please?
public function Approve1($id)
{
// For database
$data = $this->ApprovalModel->requisition_approval(array('hod'=>'submit'),$id);
if($this->db->affected_rows() > 0)
// PHPMailer object
$id=$this->uri->segment(3);
$email=$this->uri->segment(4);
$response = false;
$mail = new PHPMailer();
// SMTP configuration
$mail->isSMTP();
$mail->Host = 'smtp.gmail.com';
$mail->SMTPDebug = 3;
$mail->SMTPAuth = true;
$mail->Username = 'xyz#gmail.com';
$mail->Password = 'xyz';
$mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
$mail->Port = 587;
$mail->setFrom('xyz#gmail.com', 'xxx');
$mail->addAddress($email);
$mail->Subject = 'hii!';
$mail->isHTML(true);
// Email body content
$loginlink = site_url() . 'login' . '"';
$mailContent = <<<HEREDOC
Dear Sir/Madam ,
Your staff asked for Manpower Request, please click this link for your approval $loginlink
<p>Thank you,</p>
<p>Cladtek HRIS</p>
HEREDOC;
$mail->Body = $mailContent;
// Send email
if(!$mail->send()){
echo 'Message could not be sent.';
echo 'Mailer Error: ' . $mail->ErrorInfo;
}
else{
$this->session->set_flashdata('flash', '<div class="alert alert-success" role="alert"> Submit Succesfully!<button type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">×</span></button></div>');
return redirect('home/manage_data');
}
}