The spam messages started two days ago and it has been consistent since.  I'm receiving these messages via the Contact Us link on the board.  Is there a way to shut it down?

Remove guest rights for contact us 

That would be ideal. . .but I have not been able to find the setting.  Can you point me in the right direction?  Thank you.

Ahhh. . .it's easy once you know the secret passage.  😉  Thank you!