Laravel Newsletter is a new package that integrates with the Mailchimp API to allow subscribing, unsubscribing, and creating new campaigns.
Here are two examples to demonstrate how easy it is to subscribe and unsubscribe users:
One advantage to utilizing the API with Mailchimp is you can bypass the required double opt-in. Freek also says that more newsletter providers may be added over time. Read his post for more details and to get the package.