protected function registerSmtpTransport($config)
	{
		$this->app['swift.transport'] = $this->app->share(function($app) use ($config)
		{
			extract($config);

			// The Swift SMTP transport instance will allow us to use any SMTP backend
			// for delivering mail such as Sendgrid, Amazon SMS, or a custom server
			// a developer has available. We will just pass this configured host.
			$transport = SmtpTransport::newInstance($host, $port);

			if (isset($encryption))
			{
				$transport->setEncryption($encryption);
			}

			// Once we have the transport we will check for the presence of a username
			// and password. If we have it we will set the credentials on the Swift
			// transporter instance so that we'll properly authenticate delivery.
			if (isset($username))
			{
				$transport->setUsername($username);

				$transport->setPassword($password);
			}

			return $transport;
		});
	}