The unstoppable advance of Google+ continues, and this time its worming its way deeper into your inbox. Google has added the ability to send an email to any Google+ user in your circles through Gmail. All you have to do is start typing a name and Gmail will fill it in with matches, even if you dont have their address. This is neat if you have a valid reason to get in touch with someone, but you might also find that people you dont know can easily show up in your own inbox. Luckily, there is a way to turn it off.
This isnt actually a completely new feature, but is rather an expansion of something that already existed in Google+. If you have it enabled, one of the contact options on your Google+ profile is to send a message. This shows up in your inbox as an email from a Google+ user the new feature is the same thing, but with two important differences. It is happening entirely within Gmail, and its on by default.
The way these messages show up in your inbox will vary depending on your settings. If the person only has you in their circles, their message goes to the social tab in your inbox (assuming you use inbox categories). Should you also have them in your circles, indicating some level of familiarity, the email shows up in the primary inbox tab. If you dont use inbox categories, everything gets dumped in the usual place. You can, however, mark a Google+ email as spam and the person will be unable to send more.
If you want to turn this feature off, open your Gmail settings and scroll down the main page to Email via Google+. In the drop down you can select who can bug you. The default is anyone on Google+ well, anyone who can spell your name. The other options are only those in your circles, your extended circles (friends of friends), and no one.
Make your choice and enjoy.