Solved Sleeper Messages

I would love to see a plugin that would relay a message made by an admin to an offline player and when or if they wake up, they see that message, for example (I'll use a real-life example), on my server there was a guy with nazi signs outside his base, I removed them but I wanted to warn him to not do it again or else a ban, but I couldn't because he was offline. Any ideas?

 

I see this is set to solved, but don't see a plugin stated to work for it?

Would you be able to tell me how this is done?