Yes. There is a great newsletter component that bundles into Joomla called Acajoom. There is a free version which we bundle into our installations. The paid version offers more capabilities, but is not always necessary. Both free and paid versions allow you to create an unlimited number of newsletter mailing lists, and to accept subscriptions to them. People do not have to register with your site to join your mailing list. The two things can be separate to maximize your mailing list.