Messaging on Google Plus

This turns out to be really difficult to figure out. I've found a description of DM on G+.

Google+ does not have a Direct or Private Message feature built in, but there is a slightly less obvious way to send a message that only one other person can receive and read. To send a direct or private message on Google+, just start typing an update in your Stream on Google+ like usual. However, you’ll choose to share that update with only that one person whom you wish to receive your private message. Then, right after you send it, click the triangle in the upper right hand corner of the post you just sent to reveal options for the post, and select Disable reshare. This will prevent the recipient from sharing the private message with anyone else, which would make it not private.

Additionally, Google+ users have the option to include a feature to allow others to email them right from their Google+ profile. Users who enable this function will have a Send an Email button underneath their profile picture. This button can be limited to the user’s circles, extended circles, custom defined users, or anyone on the Web. As a result, you may only have limited ability to send an email to other Google+ users as a way of sending a private or direct message. If you want to enable this function for yourself so others can send you an email via Google+, just visit your own profile and click the blue Edit Profile button, and then click the email button under your photo.

Read more at http://www.lockergnome.com/social/2011/07/11/how-to-send-a-direct-or-private-message-on-google/#uFaBzzCuIdY6B78Z.99

you click someone's name to open the profile and just below the profile photo , there's a "Send an email", which constitutes a DM since you have to have a gmail account to have a g+ profile, and as everything is integrated...NO THERE IS NOT A SEND AN EMAIL LINK UNDER THE PROFILE PICTURE!!!!