Form Submission from Forwarded Email
If an email is forwarded to a co-worker or friend, and they use a different email address when filling out the form, HS should not update the contact the email was intended for. It should have created a new contact in the system, especially if its on a different computer.
By having the cookie over rule the email address submitted, it means you are defeating the whole purpose of getting new names from our inbound activities. Plus without realising the change has occured, you now are sending the wrong person information intended for the original person.
This is a bad practice all the way around.