Many enterprise customers leveraging Exchange Online archive their mailboxes on a regular basis to keep them clean, comply with legal requirements, and stay within the limits of mailbox storage quotas. However, the drawback of relying on time-based archiving policies only is that, depending upon your incoming data as AI-generated summaries, your mailbox volume can suddenly balloon and hit its limit, without time-based archiving criteria being met.
To work around this issue, Microsoft is "reimagining" the archiving process through a new feature called Auto-Archiving. Basically, the traditional time-based archival process moves old emails to the archive, but as described previously, it is not foolproof. Auto-Archiving is proactive in the sense that as soon as your mailbox utilization quota crosses 90%, it will begin moving your oldest emails automatically to the archive. This ensures that there is no disruption in business continuity.
The mailbox utilization quota will be continuously monitored by the Managed Folder Assistant. It will automatically begin moving your content as long as an archive mailbox is configured and it has remaining capacity.
Of course, IT admins may have many questions about this process, and Microsoft has tried to answer several of them in its dedicated FAQs section here. Among those is a clarification that items with the "Never Move to Archive" tag won"t be moved. Additionally, Auto-Archiving is not capable of autonomously provisioning an archive mailbox on behalf of the user if one has not been manually configured, and it does not have the ability to trigger an auto-expanding archive either.
Importantly, Auto-Archiving will begin rolling out for worldwide customers from October 15 and will be made available to government customers from November. It is impossible to disable this feature as Microsoft is characterizing it as a failsafe mechanism that has no known or visible disadvantages at this time, at least.