Can I block contacts?

I'm a rookie blogger on WordPress.

I've got Constant Contact and reCAPTCHA plugged in, and I'm not sure how to set them up to filter and block spam contacts, (it's my understanding they're meant to help with this).

I get an email from a particular sender through my contact form every day.  This is the notice I get:

This e-mail was sent from a contact form on Myths, Lies, and Mercy (https://www.mythsliesandmercy.com)

Thanks in advance for any help that's offered.