Is possible to add email features?
No, it is not possible. The plugin is developed for the Active Campaign service, rather than email marketing.
Can I add all users to a specific list on registration?
No, unfortunately, this is not possible. The Active Campaign only allows saving customers’ information if they go through the checkout process, so no way to add customers to a custom list when they register.
Yet, you can automatically add customers to specific lists thanks to the Deep Data integration.