A As at 25 October 2016, this feature has been disabled.
You may receive updates by "watching" a space. Click the "Watch" button at the top right of the page.
More details at https://confluence.atlassian.com/doc/watch-pages-spaces-and-blogs-139579.html
When the feature is enabled, a 'Recommended Updates' email is automatically generated for users who have this enabled and is sent weekly, see example below. More details are available at https://confluence.atlassian.com/doc/configuring-the-recommended-updates-email-notification-281480712.html
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