Lead created without email address

[Jayant_Singh]

We have created a Marketo landing page with two hidden field in which one field(email) pre-filled is enabled and another field(unsub) is disabled.

Problem: - in database blank lead is being created. What are the possible scenario for this case when blank lead is created and how should it can be fixed? 

[Steven_Vanderb3 · Accepted solution]

Someone filled out the form by navigating directly to the page rather than clicking a link in an email. Pre-fill only works with links that contain mkt_tok values, and those come from emails. I've seen this configuration cause so many issues (especially in scenarios where emails are forwarded to others) that you may want to reconsider keeping the email address field hidden from the user.