gistfile1.php

foreach( $toEmail in $listOfEmails ){
   $message = Swift_Message::newInstance()
        ->setFrom(sfConfig::get('app_sf_guard_plugin_default_from_email'))
        ->setTo( array(toEmail) )
        ->setSubject("...")
        ->setBody( "..." );
    sfContext::getInstance()->getMailer()->send($message);
   sleep(5);
}