avoid timeout in Swiftmailer

I am using swiftmailer and throttler to send emails, the problem is that the browser does timeout because the throttler makes some pauses to keep the sending within limits (5 emails per minute), I think the script continues to run Is this a problem? Is there a way to avoid timeout?

// Use AntiFlood to re-connect after 100 emails
$mailer->registerPlugin(new Swift_Plugins_AntiFloodPlugin(50));

// And specify a time in seconds to pause for (30 secs)
$mailer->registerPlugin(new Swift_Plugins_AntiFloodPlugin(50, 30));



// Rate limit to 100 emails per-minute
$mailer->registerPlugin(new Swift_Plugins_ThrottlerPlugin(
  5, Swift_Plugins_ThrottlerPlugin::MESSAGES_PER_MINUTE
));

// Rate limit to 10MB per-minute
$mailer->registerPlugin(new Swift_Plugins_ThrottlerPlugin(
  1024 * 1024 * 10, Swift_Plugins_ThrottlerPlugin::BYTES_PER_MINUTE