Please take the most recent version of the NMS Formmail script, and add a captcha to prevent automated submissions.
Formmail Script is to be called once to generate the captcha image, perhaps passing it a variable "captcha_generate=yes" to cause it to return an image instead of sending mail. Script then can be called again when the form is submitted.
Please use a relatively short captcha using either words or just random letters and numbers. Please make the captcha fairly easy to read so as to make it easier on the user. You may choose to implement a premade freely available captcha solution of your choice.
Please keep this simple, no additional functionality please. Provide basic installation instructions. Insert all code into the "USER CUSTOMISATION SECTION" of the NMS Formmail script, so as to keep the rest of the script in it's original form. I would consider a captcha solution written in PHP also, if you prefer. Well commented code is important to me.
I would like this project to be tested on the programmer's server, with an working demo provided prior to payment.