The script operates by iteratively reading all the form fields from the submitted form via the form ACTION tag. Next the script begins to build an e-mail message from the submitted fields, typically concatenating the name and value of each submitted form field in the body of the email message.
The script uses several specially-named hidden fields to control the operation of the script. The various hidden fields control who the recipient of the e-mail is, what the email subject is set to, etc. Finally the script e-mails the form's contents to the recipient(s).
The typical FormMail script has this common functionality:
More advanced variants of the script have additional features such as: provide for e-mail attachments, prevent form spamming, save the e-mail to a file or database, add CAPTCHA validation and more.
Today a variant of the script exists for most popular web scripting languages, such as Perl, ASP (ASP.NET), PHP, ColdFusion, and Java.