If you are a Gmail user and also have a Google+ profile, you are now able to email other Google+ users without requiring their email addresses. According to Google, this is intended to facilitate communication between people who know each other but have not exchanged emails yet. In addition, Gmail will suggest your Google+ connections as recipients when you are composing new mail.
For users, this means that anyone can email you as long as he or she follows you on Google+.
Following on Google+ does not require user permission; however, your email address will only be visible to the user when you respond to the email message. Messages from your Google+ followers will either land in your Primary or your Social tab: the Primary tab, if the sender is in your Google+ circles and the Social tab, if you yourself don’t follow the sender. Users that you don’t follow will be able to start another conversation with you, when you respond or add them to your circles.
The feature is automatically enabled for all users, but you can opt out by checking your Gmail settings and clicking the General tab. Find the “Email via Google+” setting and click the drop-down menu. Choose to receive email from: anyone on Google+, extended circles, circles or no one. Select your preference and click on Save Changes at the bottom of the page.
This is the latest of Google’s efforts to further integrate Google+ with its other products.
Google has repeatedly expressed its intention to develop broad and deep integrations between Google+ and its other services, web applications and sites to make it a common, underlying social networking layer. Already, there have been varying degrees of integration with Blogger, YouTube, Apps and other products already.