The requirements we have for email notifications on our site are quite generic. We want users to be able to selectively subscribe to notifications of various content updates and comments and to choose how they receive the notifications. Nevertheless there does not appear to be a single module that does what we want. The subscription module comes close, but does not handle subscriptions to organic groups. Of course organic groups handles subscriptions itself, but does not allow the flexibility to subscribe to individual content or content types. Using the subscription features from both modules leads to duplicate notifications.
I currently believe that the way forward would be to develop the subscription module further and to change other modules like og so that they do not use their own subscription infrastructure but instead plug in to the subscription module. I would be interested in the views of members of this group on whether the subscription module is indeed the most promising candidate for the main subscription engine.
Also, because we have a research grant that has a small amount of funding for development of our website we could sponsor some of the necessary development. I will post more details about that once the discussion has progressed a bit further.
You can read more about the email subscription requirements on our site at http://www.transit.york.ac.uk/node/45
Comments
UI
Yes, I agree that this is the way forward. Folks can help by thinking about the UI that subscriptions should present to its end users (and admins). How to present the wealth of subscriptions options to users? I think admins often only want to show a subset - how should they specify what appears and wagt does not? Discuss at http://drupal.org/node/189977