By default, Alfresco sends out automated notification summaries daily to members of a site for "Activities" that happened in those sites, e.g. new documents uploaded, documents modified/updated, or deleted. This by default also includes downloads / previews, but these are typically disabled in the region I work in due to worker tracking protection legislation. Apart from users being in a site, having a valid email, and a properly configured outbound SMTP setup, there is actually nothing that should need to be done to activate this, as it is active by default and rather requires explicit deactivation.
