Unfortunately, Sitefinity does not provide Email list module for the time being. But we have plans to implement such functionality in the future. So you can create your own intra site email module that will cover only basic things and after that we will help you to migrate it to ours when it is realized.
We would recommend that you have a look at the implementation of Jobs Intra Site module
which is a part of Sitefinity installation. Also, you will find useful information for building a module in this Sitefinity blog
Hope this will help you to start your research.
the Telerik team