Mail plugin bug

This was my situation: I join the server and get as normal when you join and you have a new mail the information that I have a new mail and that I can check it out with /mail read. This is the problem: So what I did was do /mail read and it told me I dont have any new messages. Also i dont know if it is normal but everytime I type in a command it tells me that I have new mail

Oh yeah here is a screenshot: https://ibb.co/y6L90b8