Settings that may prevent emails to land in a recipient's inbox

Im wondering if there are any settings that might prevent emails from jotform getting to the recipient. or is the service pretty much spam proof?

All emails may have a tendency of landing into spam, so I can't really say if there is anything that is spam proof. There are instances where JotForm would not send emails to the recipient. One of which is that if at one point, the recipient's mail server blocked JotForm's email delivery. By this, subsequent emails will no longer send unless the email address gets removed from the system's bounce list. 

You may also review your email activity history in order to understand/view the status of your forms' email alert deliveries. You can refer to this guide for more information: https://www.jotform.com/help/293-How-to-View-All-Your-Form-Email-History