Scam emails from contact form on my website

For the past 2 weeks, several times a day, we are receiving what we believe are scam emails that are being generated through our "Contact us" form on our website. We've never experienced this problem before. These messages seem to come from different emails, and the people write one word. They do not respond to our reply.

What is going on? Is it time to make a new website with a new company? We've been with Homestead for many years.