Understood. Note that, apparently, if you DO respond to one of these messages, the original sender is actually provided with your email address. Here's the text

Understood. Note that, apparently, if you DO respond to one of these messages, the original sender is actually provided with your email address. Here's the text of a message I just received from Google: "How it works with email addresses Emailing Google+ connections works a bit differently to protect the privacy of email addresses. Your email address isn't visible to your Google+ connections until you send them an email, and their email addresses are not visible to you until they respond. "