Microsoft 365

Exchange Online – Get total size of all mailboxes

Wouldn’t it be good to have an easy way to get the total size of all mailboxes you host in Exchange Online? Yes?

Challenge accepted! Using the new Exchange Online PowerShell module V2, it is a simple 1-liner. The following command will give you the sum in Megabytes:

((get-exomailbox -ResultSize Unlimited | get-exomailboxstatistics).TotalItemSize.Value.ToMB() | measure-object -sum).sum

6 replies »

  1. Hi,

    Thanks for the script,

    But unfortunately, I’m getting the below error:

    You cannot call a method on a null-valued expression.
    At line:1 char:1
    + ((get-exomailbox -ResultSize Unlimited | get-exomailboxstatistics).To …
    + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull


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