This topic was touched on in a previous thread thats now closed.

Im looking to be able to send private messages as admin to players on the server through RCON or console.
Couldn't find a command to do this.
Is this support available? Is this related to the plug in or should i contact rcon?

Per the original thread's last post:

Until this is added, I can look into adding an option to send PM's to players from the console. If that's what you are talking about?

thats exactly what id like to do. I have a remote app on my phone for rcon but no way of sending players individual messages when i'm away from the pc. I can only communicate through server chat and i'd like the option to talk to individuals. 

Commenting to add support

In the configuration:

"EnableLogging": true,