Resurrect Subscriptions plugin?

[neonacorns]

For my particular use case (keeping less active users engaged with content on a private multi-user site), I would like for users to be able to subscribe to creation of and interaction with content other than their own.

Ideally, I could provide a daily digest of activity or even simply a <= once per day email that activity has occurred.

Toying with this code, I got emails operational but with undesired results (real-time emails sent to all subscribers for effectively every user action -- accept invite, like, comment, etc.). N.b. -- I am not a coder.

Is this plugin effectively superseded by any functions in core? I considered creating RSS-fed daily digest emails, but could not get my reader to authenticate to the private site.