Has the client checked his spam folder?  Have you verified that the e-mail address is correct?

HI there, 

He has checked his spam folder, and I did double-check the email. 

I was wondering about pop-up blockers maybe? But, no one else has had this issue. I've had a few not being able to get through the security questions before, but I haven't had a client simply not receive it. 

So frustrating! 

Dawn