We are using an old version of Zen Cart (Zen Cart v1.3.7) for our Webstore and recently ran into a problem with an automatically generated email which is not sent.
When credit card payment is activated and the customer clicks on the checkout button the error message "Email Error: Could not instantiate mail function." is displayed. One autmatically generated email is sent to me, the other one which I need to complete the ordering process is not sent to me.
The server on which the store is installed has been restarted but that did not fix the problem.
I am looking for somebody with Zen Cart experience who can quickly locate and fix the problem. This project should not take more than 4 hours.
Upgrading to a newer version of Zen Cart is not an option since our templates would not work anymore and we will get a new shop system in a few months anyways.