[Plugin: Email Subscription Box After Post Content] Plugin results in error: “The feed does not ha

I installed and activated this plugin and then set up my Feedburner feed for the site, the went to settings and configured for the feedburner feed. Then, when I went to an individual blog post and tried to subscribe, I got this message:

“The feed does not have subscriptions by email enabled”

After looking at forums and exploring the Feedburner site, I still can’t figure out how to fix this. Any help would be appreciated.