Few users having issue when receiving calendar invite (Recovery Mailbox -SubstrateHold - Full) .

Regular Visitor


Few users having issue when receiving calendar invite. Meeting organizer receives warning messages saying mails cant be moved to deleted\recovery milbox.

When verified Recovery mailbox is 100 GB and mostly used by Substrate Hold. As per MS, its something related to TEAMS deleted items container. The problem we are facing is to clear\delete mails from this hold. MS is asking to use MFCmapi from user machine as there is no way it can be done from powershell or admin portal.  


Please guide me, if there is any option, to do a clean up of recovery mailbox including the substrate hold.



1 Reply
best response confirmed by sabir_rm007 (Regular Visitor)

@sabir_rm007 Substrate data in this case should be teams 1:1 chat,private channel messages, group chats etc. It appears you have hold (litigitation/legal/inplace) enabled on the mailbox, which is why office 365 is trying to preserve teams chat data in the mailbox.

If there is a hold enabled on the mailbox, i dont think even mfcmapi can help. First you need to remove the hold and then proceed with deletion. When you remove the hold, based on the retention policy applied to the mailbox, items from recoverable items should start getting purged. You can run Start-Managedfolderassistant to queue running of managed folder assistant on the mailbox. In good old days you could run "Search-Mailbox -Identity -SearchDumpsterOnly -DeleteContent" to purge content from recoverable items, but I guess Search-Mailbox was being discontinued last i checked. Ref article to get the mailbox ready :