If you see the FeedBurner error message above, this means that you need to enable the subscription by email option in your FeedBurner account settings.
It could also mean that you have not obtained the correct FeedBurner ID.
How to fix:
– Login at http://feedburner.google.com/ and select your feed.
– Go to the “Publicize” tab.
– Open the “Email Subscriptions” section on the left.
– Make sure that “Email Subscriptions” are enabled