They're a work in progress, but [Sprout Email](https://sprout.barrelstrengthdesign.com/craft-plugins/email) and [Sprout Lists](https://sprout.barrelstrengthdesign.com/craft-plugins/lists) can support some scenarios like this and are working toward supporting more use cases.

Sprout Lists lets you define a Subscriber List and allow users to Subscribe to it. A Subscription can be any relationship between a Subscriber/User and another Element, such as a Blog Entry. If you just want a generic list, you can have users Subscribe to a List Element (provided by Sprout Lists).

Sprout Email lets you setup Notification Emails that are triggered by events, and those Notification Emails can be sent to Sprout Lists Subscriber Lists.

In your situation, you could set up a Notification that was triggered whenever a new entry was created in a specific channel, and send a dynamic Notification with into about what was updated to everyone on the list.

_Note: As of this post, Sprout Email is not doing anything too fancy when it comes to sending to a list, so if your list size grows, you may run into a scenario where more optimization needs around managing larger lists. We have plans to address that scenario but it's likely that won't happen until Craft 3 or afterwards. Reach out to the Sprout team if you have any questions._