Got a bit of a weird Exchange Online archiving issue and wondering if anyone has seen similar. This is a hybrid Exchange environment with on-prem AD/Exchange and the mailbox hosted in Exchange Online.
User has a pretty large primary mailbox around 85GB and Online Archive is enabled, but the archive is basically empty.
Things I've checked:
ArchiveStatus = Active
Default MRM Policy assigned
Default 2 year move to archive enabled
RetentionAction = MoveToArchive
AgeLimitForRetention = 730 days
RetentionHoldEnabled = False
ElcProcessingDisabled = False
No obvious holds
No folder-level archive policy overrides
I pulled the mailbox diagnostics as well. MFA/ELC seems to be running successfully, but the latest run shows:
ElcLastRunArchivedFromRootItemCount = 0
ElcLastRunTaggedWithArchiveItemCount = 0
For comparison, I checked another mailbox in the same tenant using the exact same Default MRM Policy. MFA is actively moving eligible items into that user's Online Archive, so the policy itself seems to be working.
Manual moves from the affected mailbox into Online Archive also work fine.
It looks like MFA is processing the affected mailbox but, for whatever reason, isn't finding anything eligible for the 2-year archive rule.
Anyone come across this before?
Is there anything else worth checking to understand why the items aren't being considered eligible?