[sp-unsubscribe-form]

This shortcode creates a form that allows a user to enter an email address and unsubscribe. The default message after unsubscribe is: 
You have been unsubscribed from all lists.

Basic:

[sp-unsubscribe-form]

All options with defaults:

[sp-unsubscribe-form placeholder='Email' btntxt='Unsubscribe' ]

Wrapping content:

[sp-unsubscribe-form]You can provide an alternate message to your users after they unsubscribe.[/sp-unsubscribe-form]