How to build an Email Diggest using Rules I am building a Website using Drupal 7. This website contains events, event-comments and event-registrations (=Registrations module):


Event

Event Comments
Event Registration



Now I need to inform users by email when:


New events are created
Existing events are changed/updated
Events are deleted
Event Comments where added
Somebody register for an event
Somebody unregistered of an event


I found the Rules module can trigger actions on these events and conditions.

BUT: I need to generate a digest/newletter with the above information once all day or half a day etc. so users don't get too much emails ;-)

Advanced (but optional) features:


If a user un-register from an event don't send him any more updates on this particular event.
Users can set their digest/newsletter interval in their profile. eg. once a day, once an hour, etc.
Maybe other content-types then events will be added to the digest system later.


Questions:


How to I best build such a digest/newletter email using Rules? What additional modules can be integrated to Rules to address this?
Can Rules-Scheduler by of any help for this?
Is there another email-module that can to this out of the box without Rules?
You may want to consider Notifications or Subscriptions. Both modules offer either immediate or digest notifications for content updates. Be aware that Notifications currently requires PHP 5.3.