Is there any alternative for it that works with Plone 6 with Volto, what would be an alternative?
i also need this man, did you happen to find an alternative ?
An alternative you can explore is GitHub - collective/collective.listmonk: Listmonk newsletter integration for Plone . It is a basic integration for the opensource Listmonk newsletter application. It runs stand alone. And the add’on communicates over its api for (un)-subscribe, and sending.
kitconcept developed this for a client. I haven’t installed and configured it myself in another project, I don’t know how much of the newsletter composition/gathering from content is also implemented in the collective package or was part of the customisations for the project.
Products.EasyNewsletter is a great add’on, but is mature, uses and is rooted in a lot of ClassicUI and also manages the sending. This is something I wouldn’t recommend doing from the Zope proecess itself [edit: nowadays]. Listmonk and other specialised newsletter apps have much better send-controls, for example to avoid overloading mailservers and spam positives.