Design Goals:

• Allow email to be sent to a list of known email
   addresses through a web interface.
• Prevent email from being sent to other
   addresses.
• Never reveal email addresses through the web
  interface.
• Contain no cross site scripting (XSS)
   vulnerabilities.
• Do not allow arbitrary code to be run on the host. • Provide adequate information in email headers
  to trace any spammers.
• Allow, but do not require, an external form.
• Server side validity checking of all data before
  email is sent.
• Optional client side validity checking of all data
  before the form is submitted.
• A default configuration that requires only a list of
  email addresses to be ready for use.
• A customizable interface that allows arbitrary
  fields.
• Easy to change the look and feel for website
  integration.