Thanks for writing us about this -- and my apologies! The long and the short of it is: we simply forgot to build in this capability. It's annoying and totally our fault and I'm sorry you had to spend time trying to figure it out!
Until we get this fixed, you can simply register again under your new email and that will mean you get our newsletter and keep accessing your "MyCookstr" (if you've saved recipes) under your old email address.
My email is firstname.lastname@example.org and my phone number is 212 513 0358 if you need any help doing this.
Thanks so much for using Cookstr -- and please do stick with us! We are going to fix this!