It is not clear to me if you can set your form to not be submitted as a secure form or if the sender chooses how to submit the form.

It appears that some forms are submitted as secure submission and some are not.  I can not find the place where you select how the forms should be submitted.  Can you set your account so that all forms are submitted regularly or is this an option that is only available for whoever fills out the form?  I hope that the question is clear....

I suggest reviewing the user guide about secure forms here 

-How-can-I-receive-SSL-Submissions

Your account will receive secure submission if you set the form to use the secure URL or embedded the form using its secure URL.

Hope this help. Let us know if you need further assistance.

Thanks.