Dev $lasttime=max($lasttime, $thistime-6);// ... don't do more than 6 seconds' worth

in qa-include\qa-app-mailing.php
changing 
$lasttime=max($lasttime, $thistime-6);// ... don't do more than 6 seconds' worth
to
$lasttime=max($lasttime, $thistime-10);
helps a lot for service providers who dont allow sending out more than 8 emails per minute . That means we need 8 seconds interval but the script currently tollerates only 6 seconds time interval. Anythiung longer that that, leads to do nothing ( not sending emails