Hi there. If a previous email was receiving these emails but no longer are, you may need to create a new email and verify it to get another code.
How do you do that? Get the email verified and such?
You can do this in your [url=https://www.bungie.net/en/Profile/Settings]Bungie.net settings[/url] in the Notifications and Email section.
Ok I changed the email. But how does it verify it?
You'll have to send yourself a Verification email. There should be a yellow button on the page that you can click to verify the email. You may need to use a major email provider, such as Gmail or Outlook, to receive the verification email. Once you receive the email, verify it on your Bungie.net account then resend the Bungie Rewards email. Make sure to click "THIS LINK" when you receive the email.