Plugin for Newsletter

Hey everyone, happy holiday,

is there a plugin to create newsletter from within wordpress? We currently use Automatewoo, for our shop but that is somehow limited.
What we are looking for is to create a custom newsletter (like with mailchimp, but we can’t use that) and send them to our customers. Mostly about news and blog posts.
Is there a plugin for it or do I have to rely on external services/template desigerns?

Best regards

exxis