One of my clients emailed me today with this odd issue - they have received some orders recently with nothing in the email or phone number fields.

Here is what she sent me:

For some reason, some of our customers are able to checkout without a phone number or email address.
I understand that some people don’t have email addresses, but we have to at least have a phone number.
We have discovered this by receiving orders that customers process themselves with either no email or no phone number. I also thought this was strange because when I try to enter an order as a customer would, it will not allow me to complete without those filled in. I have however tricked it by hitting the spacebar 10 times and getting past the phone number ;)