Depending on how you look at it, Google now has a very useful or very creepy new use for Google+: The search giant is allowing Gmail users to contact any Google+ connection, regardless of relationship.
Didn't exchange email addresses with a business colleague or personal acquaintance, but suddenly need to get in touch? Just type the connection's name into the email's recipient field, and send your message.
This move, according to Google product manager David Nachum, is an extension of some 2011 improvements to the email service and social network which help users grow their circles, filter emails and contacts, and automatically keep all data up to date.
"These emails work a bit differently so that your email address is only shared with the people you want," Nachum wrote in a blog post. Your address will not be visible to a Google+ connection until you actually send a message, and vice versa.
But if you're just using the network to stalk friends' photos or keep up with daily news, and don't want anyone with a random connection to start spamming your inbox, just adjust your settings to an appropriate level of access — anyone on Google+, extended circles, circles, or no one.
The update also takes advantage of Gmail's new inbox categories: When someone in your circles emails you, the message will drop into the Primary category. Those Google+ users not yet categorised will be filtered into the Social category, and will be able to start a conversation only once you respond or add them to your circles.
These features are rolling out over the next couple of days to all Gmail and Google+ users, who will receive an email with information, and a link to set up the feature when available.