The Archiving Plugin archives Confluence pages that haven't been changed for awhile, or have been labelled with 'archive'. This plugin helps you to keep your content fresh and relevant. Pages that never expire and are to be ignored by archiving should be labelled with noarchive or noarchive-single.
For each fresh space having pages to archive, it will create an archive space transparently in the background. Then it copies the outdated pages there, and trashes the original ones. Additionally, it sends emails to authors and last modifiers of the pages close to expire.
It effectively automates content archival processes, and prevents your wiki spaces turning into scrap-yards.