If your customer bought tickets and did not get their ticket download URL, you can easily re-send their confirmation email to them. 

In your back admin dashboard, navigate to My Ticket Space > Orders and locate the person's order. Open the order by clicking on the "Edit" button.

Next, you will be presented with their order details in the back end, scroll to the bottom, and you will see the "Re-Send order confirmation e-mail". Click on that, and it will send it again.

If your customer still does not receive it, have them check their Spam folder as well. If you encounter any other issues, please contact us and let us know.