Hi Iris,
You could use the Moodle built in messaging system and send the info directly to the manager. But then everyone can start using messaging too.
If you can install addons, or have someone do it for you, you could use Jmail or Dialogue both of which have Moodle 2.7 versions. I don't use Jmail anymore as I don't want the added responsibility of monitoring emails between students, like I had to do in the past.
I personally use the Dialogue activity on the front page of my Moodle. I don't remember how I set it, but I have it so that students can open a dialogue ONLY with me, but I can open one with anyone. It allows us to have one-on-one, back-and-forth private conversations. Once a matter is resolved, the dialogue can be closed, but kept for reference. They can also be deleted, if you wish to.
HTH,
AL