My subscribe have a problem

hi all, I have questions. I use the plugin “WP Subscriber Form”. when i signup my email, its display a description like this “The feed does not have subscriptions by email enabled” and “Welcome back,[email protected] (example of my primary email).”the true is , i didn’t sign up with that email. to be honest I’m not very understand with FeedBurner system.

thanks for the attention …