Captcha image not visible

Have you tried to check the info in this post:

cPanel | Most common contact form issues

as well as this article

https://help.sitejet.io/hc/en-us/articles/32201735492503-Most-common-questions-about-the-contact-form

?

From your screenshot I can see that a sender address is missing. Unless you are using Sitejet Studio, as explained in the article and the community post, this will definitely not work.

Try this out first and let us know.