If you're receiving a blank email, it's possible that the form is missing name attributes.
Formspree needs a name attribute on every input field for it to be received, and included in email notifications or sent to plugins. Actually, it's not just a Formspree thing, it's how all HTML forms work. Without name attributes, the input values aren't included in the submission data.
Here's an example of an input field asking for an occupation with a good name attribute:
<input name="occupation" type="text" placeholder="Doctor, Comedian, etc.">For more examples, and inspiration, check out our form library.