Godaddy Mail Glitch & Php

1.I have a newsletter script purchased from phpjabbers dot com that will send out the initial “thanks for subscribing” email but the newsletter messages are saved but never sent out. I need that sorted out and working. I hear its due to Godaddys php mail fuction but cant say exactly.

IMPORTANT NOTE:
-Hosted with godaddy
-Only FTP access is provided
-Must be fixed without access to phpmysql or Godaddys direct hosting panel.