Exchange-Online-PowerShell-Recipes

Find the Largest User Mailboxes

Problem

You want to find the largest user mailboxes by the total size of all items.

Solution

Get-ExoMailbox -RecipientTypeDetails Usermailbox -ResultSize Unlimited |
Select-Object -Property Identity |
Get-EXOMailboxStatistics -PropertySet All |
Sort-Object -Property TotalItemSize -Descending |
Select-Object -Property DisplayName, TotalItemSize -First 10

Discussion

If you have a large organization, this could take some time to execute. Adjust the -First 10 to suit your needs. This recipe can be modified to find other properties. Using the Get-EXOMailboxStatistics -PropertySet All provides access to all the properties1.

Example

Change this recipe to find the largest user mailboxes by item count instead of total item size.

Get-ExoMailbox -RecipientTypeDetails Usermailbox -ResultSize Unlimited |
Select-Object -Property Identity |
Get-EXOMailboxStatistics -PropertySet All |
Sort-Object -Property ItemCount -Descending |
Select-Object -Property DisplayName, ItemCount -First 10

References

  1. Get-EXOMailboxStatistics Property Set documentation ↩

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