If there is already a way to message players whilst they are off-line, or in other Snapcraft servers, I apologize. It was brought to my attention, while trying to send /mail to a friend - that I had lacked the necessary permissions. ( Essentials.mail.send ). I know there are other ways to contact friends such as the forums, and Discord. I just feel as though it would essentially be useful; to be able to message players who aren't online at the moment, or whom aren't in the same server as you.