I do not know if this might be reason, but I haven’t gotten my e-mail yet. Two of my friends who have played halo 4 before the 20th, had their e-mail linked with hotmail and they had received the e-mail. I did not have it linked and some of my other friends that did not have it linked had received the e-mail.
In my opinion, could it be that some of us did not link our email to hotmail, that is why we did not receive the e-mail? I just linked my e-mail to hotmail a few minutes ago.
I am probably wrong, but it is just my opinion