Overview

• General availability begins October 15 for public clouds, with government cloud rollout slated for November.
• When a mailbox crosses 90% of its quota, the service moves the oldest items—including eligible recoverable items—until usage drops below the threshold, preserving folder structure and searchability.
• Auto-Archiving runs only if an archive mailbox already exists with available space and it will not provision archives or enable auto-expanding on users’ behalf.
• The feature is a non-disableable failsafe that temporarily overrides time-based policies, honors items tagged “Never Move to Archive,” and continues even under Retention Hold.
• The Managed Folder Assistant monitors mailbox size with an execution SLA of up to seven days, and administrators can audit activity via Exchange Online diagnostic logs.