activation e-mail problem to hotmail

Hi

My invited friend didn't receive the invitation to hotmail e-mail.
He registered manually succesful with the code but he doesn't receive the activation e-mail now.

How could he solve this problem?

(it isn't in the spam folder either)

edit: here is his profile:
https://www.forumophilia.com/profile.php?mode=viewprofile&u=310242

is it possible to change his e-mail to gmail?

How could we solve this problem without re-invite?

account activated