Adding to a users email

I want to customize the email sent to the user upon activation to say it will take 24-48 hours to approve.

I thought this would do the trick bit did not see it on the email:

<p>Dear [#user_name#],</p><p>You can log in with the following information:</p>[#login_details#]<p>You can login here: [#login_url#]</p><p> Please be aware that all registrations must be approved. This usually takes between 24-48 hours. Thank you,<br /><br />[#site_name_url#].</p>

This did not show up before “Thank ?You.” How do I make this visible?