Daily or Weekly Digest Module?

Hi all,

I have created a custom content, called email_digest, using CCK. Site users can create email digest nodes by sending an email using mailhandler.module or by via the "create content" link. All of the post are displayed by time created using views.module. Taxonomy terms are also used to tag how the post was added (email or web).

Is there any way for the new email_digest content to be emailed to users who subscribe to receive a daily or weekly updates? I've tried subscriptions.module, but would really like to have the option of a "receive weekly updates" option. If you haven't guessed, I'm trying to replicate a Yahoo! group.

Any suggestions would be greatly appreciated.