Autoresponder Repair

I have an autoresponder service that is now experiencing problems when emails are sent out to subscriber lists with over 6,000 subscribers. There is an error message saying that the emailing of a large list is still in progress when the mailing has had more than enough time to be sent.? The system is locking up and no emails are being sent.? On most smaller lists the system is working properly.? It seems to be getting worse because the size of the list being mailed to is getting smaller and locking up.? It started locking up when the lists were over 10,000 subscribers.? I need you to go through the script and repair the cause of this error.? This is a cgi script and uses perl to function.? So good knowledge of Perl and cgi are necessary to accept this project.? A knowledge of how an autoresponder functions is a plus and will make your work easier. All details and access to the autoresponder site will be available once your bid has been accepted.