General notification

Hi,

first of all: I like Jisko. Keep up the good work!

Feature request:
It would be nice to have an option to recieve email notifications when users post messages.
To avoid many emails many messages could be aggregated into one mail.
E.g.: Make it max. 1 Mail/15 Minutes (or 30 or 60...)
12:00: User posts a message -> mail to followers that subscribed the notification option
12:01: Another message -> nothing happens as the other message is only one minute ago
12:10: Another message -> nothing happens
12:25: Antoher message -> all messages since the last one are sent in one email

What do you think?

Cheers,

bja