Key Points:

• The verification email should arrive within thirty minutes, and expire in one hour from when they are sent.

What to Do:

• Check your spam/junk e-mail folder to see if the e-mail is there.
• Make sure there are no filters in your e-mail account that may be blocking e-mails from @accounts.nintendo.com.
• Make sure that you are entering your e-mail address correctly in the account creation screen, and click "resend verification code" to have a new verification code sent.
• Try registering your Nintendo Account with a different e-mail address