Check Office 365 Mailbox Size

Do you need to check the mailbox size in office 365?

In this guide, I’ll show you two methods to find the office 365 mailbox size.

Method 1: Find Office 365 Mailbox Size Using PowerShell

You need to have the Exchange Online PowerShell V2 Module installed. You can install this module with the command below.

Install-Module -Name ExchangeOnlineManagement

Once installed you will need to run this command to connect to Exchange Online. This command support MFA.

Connect-ExchangeOnline

Get mailbox size for a single user. Change identity to the email address of the user you want to look up.

Get-Mailbox -Identity robert@activedirectorypro.com | Get-MailboxStatistics | select DisplayName,TotalItemSize, ItemCount

To find the office 365 mailbox size for all users use this command.

Get-Mailbox -ResultSize Unlimited | Get-MailboxStatistics | select DisplayName,TotalItemSize, ItemCount

You might get a warning like I did if you have any mailboxes that have not been signed into.

That is it for method 1.

Method 2: Find Office 365 Mailbox Size using Exchange Admin Center

This method only allows you to check one mailbox at a time.

Step 1: Go to the Exchange Online Admin Center

Step 2: Go to Recipients and click on any user

Mailbox usage details are displayed in the lower right.

Recommended Tool: Permissions Analyzer for Active Directory

This FREE tool lets you get instant visibility into user and group permissions and allows you to quickly check user or group permissions for files, network, and folder shares.

You can analyze user permissions based on an individual user or group membership.

This is a Free tool, download your copy here.

1 thought on “Check Office 365 Mailbox Size”

  1. Hi Robert
    Thanks for the tips. I love handling my daily task as administrator using Powershell. Once I have find the right command-lets. I do find it much faster to handle these tasks using PowerShell.

    Reply

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