Yes, if you delete a message, the associated attachments are automatically deleted. If you delete a topic, all the attachments associated with the messages in that topic will be deleted.

Also, after thinking about it yesterday, I've moved the new Attachments page. To access it now, go to the Billing or Upgrade link in the sidebar in the Admin dropdown. It's not a useful page for anyone other than group owners, so having it as one of the archive views didn't make sense to me.

Thanks,

Mark