OK, sometimes I am slow on the uptake - I'm rapidly approaching 60, so it's beginning to be expected. I don't always think on various planes, at once, like I used to be able to. Sometimes, the penny doesn't drop for a little while.
A blogger, named Jack, asked a routine question in the Help Forum re: Email Subscription to Comments. As I use a Full Page for Comments Form Placement, I didn't see the option which is available - ONLY - in Embedded Below Post Option, on the Settings - Comments screen.
So, I wasn't aware that this feature existed. I thought it might be passé. Blogger doesn't always update the Help. Then, the penny dropped for me, today.
The Blogger Help article, called "How do I subscribe to comments by email?", which Jack came across, diligently searching through Blogger Help archives, shows NO indication that your blog Comments Setting must be "Embedded Below Posts"!
The Blogger help article also says;
"In order to subscribe to comments by email, you must be logged in to a Google Account. Please log in with the account using the email address at which you'd like to receive the comment emails. As soon as you're logged in, you'll be taken to a confirmation page where you can click "Subscribe" to opt in. On this page, you'll also have the option to use a different Google Account to receive comment emails."
Naturally, that is NOT the case, as I found out.
There is no confirmation screen for 'opting in' to a Subscription, and there is certainly no option to use a different Google Account to receive comment emails, unless you change it on the Comments Wizard - BEFORE you subscribe!
Unsubscribing is just as simple. Click the Unsubscribe button ...
The Help article also says;
"You can unsubscribe from comments by email at any time; just click the unsubscribe link in the comment emails you receive."
On reflection of the benefits of this feature, which I believe to be very few, I could not see myself using it in preference to a Comments Feed, or a Blog Feed.
There's also the email Follow-up to Comments in the Comments Wizard.
Remember: This feature is a per-post comment Feed, only.