Update 10/17/2025: We updated the content of this blog post, the timelines and the FAQ to align with customer feedback we received after initial announcement.
TL; DR: A new capability called Auto A...
Updated Oct 17, 2025
Version 5.0
Blog Post
Hello, "When a user's mailbox utilization exceeds 96%" which quota is it IssueWarningQuota, ProhibitSendQuota, ProhibitSendRecivingQuota?
When a user's mailbox utilization exceeds 96%, it does not directly correspond to the traditional IssueWarningQuota, ProhibitSendQuota, or ProhibitSendReceiveQuota.
Instead, this threshold is part of a new feature called Auto Archiving for Exchange Online "AutoArchivingThresholdPercentage", which is designed to proactively manage mailbox size before hitting those traditional quota limits.
Key Clarification:
96% utilization is the trigger point for Auto Archiving, not a standard quota like IssueWarningQuota.
Auto Archiving begins only if:
- The archive mailbox is provisioned.
- There is remaining space in the archive.
It moves the oldest items (excluding those tagged “Never Move to Archive”) from the primary mailbox to the archive mailbox until usage drops below 96%.
Summary:
- 96% utilization is now a failsafe threshold for Auto Archiving "AutoArchivingThresholdPercentage"
- It is not the same as IssueWarningQuota.
- It is designed to prevent reaching ProhibitSendReceiveQuota by acting early.
AniketgMicrosoft
It is ProhibitSendReceiveQuota
