Just wanted to followup for anyone that finds this post.
THIS WAS THE HOSTS PROBLEM - NOT THE EMAIL SCRIPT.
eventually all the emails that were previously blocked went out. so for orders placed in july - the email confirmations went out in september. this was horrible for my client!
i highly recommend using a different hosting solution.
When i called tech support to alert them to the issue of OLD emails going out, i was disconnected 2 times. i dont think it was by chance.