Subscribe to Site - not showing in front end

I'm having ahard time allowing site visitors subscribe to the whole blog via email. Individual categories and individual authors have an envelope icon below the category/author name. But All Categories doesn't show an icon and there is nowhere with a link to "Subscribe to bloG".

May be in making various config changes or customizations, I have turned off this capability. Can you tell me how to restore this.

I have added a subscribe module on the All Categories page, but I'd prefer to see the icon below the All Categories title or somewhere on that page or on blog pages.
Thanks,
Andrew