E-mail not always sent

I'm trying to send emails, but I do not always receive emails

File config email

PHP Code:

<?php if (!defined('BASEPATH')) exit('No direct script access allowed');

$config['smtp_port'] =25
$config['smtp_timeout'] = 5;
$config['crlf'] = '\r\n';
$config['newline'] = '\r\n';
$config['wordwrap'] = FALSE;
$config['mailtype'] = 'html';
$config['charset'] = 'UTF-8';
$config['wordwrap'] = TRUE; 


File Controller

PHP Code:

…
 $message= 'Data login',
 $link_base=base_url('login');
 $message=email_template($mess_email, $link_base);
 $this->email->from('[email protected]','Online service');
 $this->email->to($email);
 $this->email->subject(lang('subject_e'));
 $this->email->message($message);
 $this->email->send();
 if(!$this->email->send()){
  $data['messaggio'] ='Errore';
   }
 else  { echo 'invio no'; }
 ... 


 var_dump($this->email->print_debugger());

PHP Code:

string(37) "lang:email_no_from

" 


Help me