I am trying to understand the mailbox size.

New Contributor

I am trying to understand the mailbox size. We have a on prem Exchange server. Please see the picture below, why is there discrepancy between what is shown on Outlook client and the Exchange server itself . Left side is the Outlook client, the right side is Exchange server one. Mailbox.JPG

4 Replies
best response confirmed by fedoracore (New Contributor)

@fedoracore What you see on ECP, whatever version of Exchange or Exchange online if you are using includes all data in IPM except Recoverable items ( deleted items in this case ) whch is shared across your IPM and non-ipm data folders.


IPM contains the default front end folders like inbox, sent items drafts , etc and deleted items (partially) , when an item is deleted from deleted items and it moves to recoverable items folder (Last chance) it moves into NON-ipm which is separate from Mailbox regular statistics and hence displays the same on ECP/Admin Center which is different from your Outlook statistics.


For Best results, always run below command to fetch statistics which will give you exact data a mailbox is consuming Technically from backend mailbox database.


Get-MailboxStatistics | FL 


Also for getting information about each specific folder and how much data your recoverable items folders are consuming - 


Get-MailboxFolderStatistics | Select Name , Foldersize , Itemsinfolder


For specific to Recoverable items run below - 


Get-MailboxFolderStatistics -FolderScope Recoverableitems | Select Name , Foldersize , Itemsinfolder


Cheers !!

Ankit Shukla


Thanks Ankit!!

I'm glad it resolved the issue as well as explained the issue for which you were looking for answer. Please mark as answer of that resolved your issue.
Actually looks like there is something else. I did not articulate it well