When a previously registered user uses my subscription form they are presented with an error message. Is it possible to add the same email address twice or to update the previous details?

By default, the application only allows the same email address to be entered once into a contact list so your subscription form will tell people they are already subscribed.

To bypass this, the application has a 'Contact Form' feature that will make the subscription form emulate a contact form.

When setting up the website form, there is an option that says: "Contact Form" on the first page. Check this option. It will then allow multiple submissions from the same email address, but will only enter the user in once to the system.

This way your subscription form will look like and function like a contact form. When someone fills it in, it will send you an email with the details AND add the user to your the application contact list.

If you choose this option, then users that are already subscribed to your contact list will still be able to fill in the form, will be sent to a Thank You page but will not be re-added to your contact list.