You no longer need someone's email address to send them an email. At least, that will soon be the case if you're both a Gmail and Google+ user and have the right settings enabled. A new Gmail setting lets you choose whether you want people to be able to send an email to your Google+ profile — even if they don't have your email address in their contacts. The four options let you control whether any Google+ user, or just people in your circles or extended circles can email you. You can also disable the feature by selecting "no one." Even if you do let people send you emails through their Google+ connection, your actual email address won't be revealed unless you respond to the email.
The change continues the company's push to integrate Google+ with the rest of its popular online services, though it will do little to make the company's third-place social network a destination. We can't say that we're excited about getting even more emails from strangers, but it's unclear what the setting will be on by default — we've reached out to Google for more information. Google says that the feature will be rolling out over the next few days, so don't worry if you don't see the settings yet.
Update: Google has clarified the change, and it seems particularly intrusive. By default, the setting will allow anyone on Google+ to send you an email through Gmail. To be clear, Gmail users will be able to type anyone's name into the recipient field and even if you don't know that person's email address. Google will auto-suggest the names of Google+ users, though your actual email address will not be revealed unless you reply to the email.