Spam issues

Hi all.

I have been experiencing problems with receiving spam messages through a WordPress site I maintain. On the site we have an online form, which when completed, redirects the answer to a functional e-mail inbox for the text to be vetted. In the last week or so the inbox has been full of spam e-mails from fake e-mail addresses.

Can anybody please advise if there is a way to stop these emails from coming through? Someone advised introducing a recapture (the function which requires visitors to input the distorted letters shown on screen) as that would stop them. Has anybody added this to their site, and if so can they advise how it was done? Please note I am very new to WordPress and have limited knowledge about coding.

Thank you

Harj