Send Email using SendGrid PHP library on Github

We are hosting the 3mik.com boxes on Rackspace right now and  we get 40,000 emails/month free of cost  from one of their partners, SendGrid. We use SendGrid to send  emails from our application written in PHP.  The SendGrid documentation suggests using SMTP relays and swiftmail-4.x library.  However, SendGrid also has a PHP front-end library published on github that makes it super easy to send emails.

Here is one complete test script

    require_once($_SERVER['WEBGLOO_LIB_ROOT']. '/ext/sendgrid-php/SendGrid_loader.php');
    set_error_handler('offline_error_handler');
    $sendgrid = new SendGrid('your-sendgrid-login', 'your-sendgrid-password');
    $mail = new SendGrid\Mail();


     $mail->addTo('foo@gmail.com')->
       setFrom('foo@3mik.com')->
       setSubject('Sendgrid github PHP library test')->
       setText('Hello World! from sendgrid library')->
       setHtml('Hello World! from sendgrid github lib');  

    $response = $sendgrid->web->send($mail);
    // Error Handling:- 
    // sendgrid->web method uses curl_exec CURLOPT_RETURNTRANSFER set. 
    // This means you will get FALSE
    // when the send method fails at network level.
    // you get JSON response back when curl is able to communicate with the server
    // success from API is returned as
    // {"message":"success"}
    // Error from API is returned as
    // {"message": "error", "errors": ["Bad username / password"]}
    print_r($response);



?>

Though all SendGrid documentation exhorts you to use SMTP, I do not see a problem in using the WEB method.  As per this SO question, http://stackoverflow.com/questions/6193702/sendgrid-smtp-or-curl , " The  web API actually works faster than SMTP, as you only need to make a single cURL request to us to send a message, whereas with SMTP there's a lot of back-and-forth TCP chatter for connection, HELO, and such." 


Error checks are crucial part of any code. Here is my complete sendgrid wrapper complete with error checks. I do not want to throw exceptions because I want clients to handle the error their own way.