If I change the e-mail on my account, it makes me re-take the rules quiz, and then I get the message from Sam welcoming me to the game. 

:/
I sent a message to Sam about this for ya! :)

I will see what we can do about that! It's set to send the welcome message after you take the quiz for the first time, but it's not supposed to make you take it when you change your email, so hopefully it'll be an easy fix :).