Plugin "Subscribe by Email": add "Never" in dropdown

In the dropdown menu of the plugin "Subscribe by email" and regarding the frequency of emailing, please add "Never". Indeed, a lot of us may want to only save the email addresses without actually having any emails being sent by the plugin. Then people can do what they want with the saved email addresses (e.g. use a third party newsletter service like icontact). This is a crucial feature. Best, Ronan