First off, I'd like to apologise if this isn't the appropriate forum to present my problem. Basically, I have a form on a jsp page that posts email information to a servlet, that sends email using JavaMail.
My problem is that it's just a form, and there is nothing to prevent the form from being abused. The destination email address is fixed and only known to the servlet, I'm mainly concerned about people sending mass email through this form with no way of preventing it.
I was thinking of making a verification image, perhaps by using JCaptcha, and was wondering if that was the best way to go about securing a form like this? Or, are there easier alternatives to get the job done?