Is there a way to retrieve the email address?

My form didn't capture the email address, is there a way to Retrieve the email address 

I think you are referring to the "Request a Quote" form, right? When I checked the submissions for this form, I could see a few test submissions, and the email field was not visible.

Your form does have the email field marked as required. Did you mark this as required, after these initial submissions? The reason for asking is that I just test submitted your form and the submission showed the email address. You can check that from your Form Submission page. If the email field was marked as required, now then there are chances that it might have been skipped during the previous submissions.

Also, the test submission dates shown in the Form Submission page are before the new changes were made to the email field. 

You can also check the revision history of changes made to the form and revert to a previous version, but probably you will not be able to get the email address if they were filled.

Please test your form now to see the email address.