Using the IdeaScale platform users can send private messages to the other users from the Leaderboard and from the idea details where you see the submitter's name. Simply click on the member's name and go into the profile of the user.
Clicking on the idea submitter's name would also give a link Send PM to the submitter.
Click on the Send PM button
Compose the message to be sent. By default, the "To" box bears the name of the user whom you have chosen from the Leaderboard. One can choose to send the same message privately to the additional users.
The Private messages sent by the user can be viewed in the member's Sent box.
The user to whom the message is sent can view the message in the 'Inbox' in the Personal Settings >> Messages
or by clicking on the envelope icon the which also shows the number of unread messages.
Clicking on the message allows the user to read and Reply to the message.
There is also an email notification sent to the user you have been sent a private message.
Help Article: "Follow / Unfollow" a member