Yes. In iLearn, this tool is called Dialogue. The Dialogue activity is a private communication channel between two people in an online unit. It is worthwhile nothing that convenors and lecturers of the online unit will be able to see any correspondence made through a Dialogue activity. You can set up multiple dialogues to host a number of different conversations, or you may only need to create one dialogue for the entire class, depending on how you want to use them.