Setting up an email subscription service using RSS
Using google feedburner you can provide opt in users with email subscription updates. These can come from any place where an rss feed is generated on your website. For example, blog posts, or comment steams.
Using your google account sign in to feedburner. Claim your feed and follow the prompts. Once your feed is claimed, navigate to the feed management dashboard. Select publicize and activate email subscriptions. There is also an option to activate extra ping services in this tab. Once activated, the email subscriptions tab will give you an option to copy paste some code (form widget) that can be used in the html of your website.
Add the code to your website.