Have a few different buttons on your email template: separate social media buttons that produce pre-written social posts linking to a webpage version of your email, and an "Email to a Friend" button that transfers the email into a compose window so your contacts can instantly forward the message. Just make sure your email has an opt-in button so each new viewer can subscribe to more emails from you if they like what they see.
A tracking pixel is a snippet of code that allows you to track your subscribers’ activity across various channels like your website, landing pages, and newsletters. Then, you also have the option to send emails triggered by certain behaviors. So for example, if a subscriber goes to your site and checks out your product page, a tracking pixel can send an email with a special offer for the specific product the viewed.