How can I stop Email Spamming?

I am fed up with a spamming issue on my website. I am getting 10 to 12 spamming mail by a contact us form. I have a packing and moving website, Cloud Packers -
In this, I have place one contact us form, by which service needed person can contact me.
But spamming make my server black listed.
Later on I have added captcha and still, I am getting spam mail.
How can stop now? Site domain is registered with hostindia-
Any suggestion?

Have you tried using Google recaptcha?