E-mail Form: Generate and process e-mail contact forms

This class can to generate and process e-mail contact forms.

It can compose a form with custom optional fields. All forms start with a name and an e-mail field.

The class can also validate and process the form by sending it to the configured site contact address. The user e-mail and the custom fields can be made optional.

If all fields are correct, the class composes and sends a message with the values submitted using the form. Otherwise, The class displays an error message and presents the form again.

The form presentation details can be customized CSS styles.