title: Symfony 2 : Swiftmailer exception
body: <p>I've been working on the Symfony 2 emails sending using Swiftmailer.</p>
  
  <p>Here is my swiftmailer configuration in app/config/config.yml</p>
  
  <pre><code>swiftmailer:
   transport: gmail
   username:  myusername@gmail.com
   host:      smtp.gmail.com
   password:  mypassword
  </code></pre>
  
  <p>I have also configured my xampp localhost to send emails.</p>
  
  <p>I have a form where user enters email addresses (max 5 emails) , Subject and Message. For first few tests on submitting the form the emails where sent. I also actually got emails. But after that i've been getting this error below repeatedly.</p>
  
  <blockquote>
    <p>Failed to authenticate on SMTP server with username "myusername@gmail.com" using 1 possible authenticators
    500 Internal Server Error - Swift_TransportException</p>
  </blockquote>
  
  <p>What is the problem over here? I also tried stopping my xampp and then re-starting it, but still the problem persists. Does any one know whats the problem here?</p>
  
  <p>Thank You.</p>