Markus Johansson from swedish Umbraco partner Enkel Media published Newsletter Studio 2.0 for Umbraco 7.
It extends Umbraco by direct and full-scale integration of newsletter functionality, right in the backend. Newsletter content can be handled directly with Umbraco. Even existing content can be published as a newsletter with a few clicks.
Administration of campaigns and recipients is seemlesly integratrated in the Umbraco backend and content structure.
As you know it from the Umbraco world, Newsletter Studio is heavily extendable und customizable for every project.
More details about the new version of Newsletter Studio can be found on the website of Enkel Media.