You were right - the email tag in required and it is now working.
Here is a brief description and the tag in case anyone else needs it.
Description: This form field will allow the user to specify their return e-mail address. If you want to be able to return e-mail to your user, I strongly suggest that you include this form field and allow them to fill it in. This will be put into the From: field of the message you receive. If you want to require an email address with valid syntax, add this field name to the 'required' field.
<input type=text name="email">