Editing your campaign for social sharing
When creating an email in your campaigns section, take a moment to click the Add social sharing options button in the top right corner of your email. By checking the boxes in the menu that appears, you're choosing the options your audience will have to share your email with their friends and followers.
Note that the email checkbox is checked by default, but you can deselect it. The envelope icon replaces the send this to a friend link that used to show up on your stationery.
Click save in the menu window, and continue editing your campaign.