We do treat it that way. But today I came across an otherwise promising application that didn't have any email addresses in it. I had to call them on the phone and leave a message telling them to add their email addresses. Obviously this does not scale.
"... I've been resisting adding lots of structure to the form so that people can email drafts around ..."
Maybe there should (a few) mandatory fields (contact email + phone + first name + last name) like a login. Leave the rest unstructured. You don't need your life details, just a username and email address that uniquely identifies users and allows contact.
