Form Spits Out Spam Error

I get the error:

There was an error trying to send your message. Please try again later.

In an orange box. Meaning its a spam error. I have tried several tests and always the same. I have checked with my smtp mail server and works fine. I have contacted the hosting and said it works fine but to contact plug in developer.

Is there any other reason for this error?

The page I need help with: [log in to see the link]