Last updated: April 13, 2021.
The Feedburner team announced that their email subscription service will be discontinued in July 2021. As a result, Blogger’s email subscription widget, also known as the FollowByEmail widget, will be turned off.
From July 2021 onwards, your existing Feedburner feeds will continue to serve but the automated emails to your subscribers won’t be supported. If you’d like to continue to send emails to your subscribers and use an alternative automated email solution, you can download your subscriber contacts.
After April 13, 2021, blogs that don’t already use the FollowByEmail widget can't enable it.