How to get mailbox size using PowerShell

Exchange admins frequently need to monitor and report on mailbox sizes to manage storage allocation, identify oversized mailboxes, and ensure optimal Exchange Server performance. This can be accomplished through several methods: The native Exchange admin center (EAC), PowerShell scripting, or by utilizing specialized Exchange reporting tools like ManageEngine Exchange Reporter Plus. Let's explore these different approaches below.

Method 1: Getting the mailbox size using EAC

Prerequisite

Before using the EAC, ensure the account you use to log in is a member of the Recipient Management role group at the minimum.

Using the Exchange admin center to get mailbox size

You can view mailbox sizes directly using the traditional EAC in the web interface.

1. Open your web browser and navigate to https://servername/ecp (here, replace servername with your Exchange Server name).
2. Sign in with an account that has Exchange admin privileges.
3. Navigate to Recipients > Mailboxes.
4. Select the mailbox you want to check from the list.
5. Click the Edit icon (✏) to open mailbox properties.
6. In the mailbox properties window, click on Mailbox usage in the left navigation pane to view the space consumption by that particular mailbox.

Method 2: Getting the mailbox size using PowerShell (Get-MailboxStatistics)

Prerequisites

Before using the Get-MailboxStatistics cmdlet, please verify that the below mentioned prerequisites are satisfied:

1. Exchange Management Shell is installed and accessible on your Exchange Server or management workstation.
2. You have appropriate Exchange Server permissions (View-Only Organization Management or Organization Management role).

Using the Get-MailboxStatistics command to get the mailbox size

The Get-MailboxStatistics cmdlet is used to return information about a mailbox, such as the size of the mailbox, the number of messages it contains, and the last time it was accessed.

The syntax for it is given below:

                                  Get-MailboxStatistics
                                [[-StoreMailboxIdentity] <StoreMailboxIdParameter>]
                                -Database <DatabaseIdParameter>
                                [-CopyOnServer <ServerIdParameter>]
                                [-DomainController <Fqdn>]
                                [-Filter <String>]
                                [-IncludeMoveHistory]
                                [-IncludeMoveReport]
                                [-IncludeQuarantineDetails]
                                [-NoADLookup]
                                [<CommonParameters>]
                            

The Get-MailboxStatistics cmdlet requires at least one of the following parameters to execute successfully: server, database, or identity.

Supported parameters

The following table contains some parameters that can be used along with the Get-MailboxStatistics command to retrieve the mailbox size efficiently.

Example use cases using the Get-MailboxStatistics cmdlet

Getting mailbox size for a single user

                                Get-MailboxStatistics -Identity "user_email_address" | Select-Object DisplayName, TotalItemSize, ItemCount
                            

For this cmdlet, replace "user_email_address" with the actual email address of the user.

Getting mailbox sizes for all users on a specific server

                                Get-MailboxStatistics -Server "exchange_server_name" | Select-Object DisplayName, TotalItemSize, ItemCount | Sort-Object TotalItemSize -Descending
                            

For this cmdlet, replace "exchange_server_name" with your actual Exchange Server name.

Getting disconnected mailboxes from all databases

                                Get-MailboxDatabase | Get-MailboxStatistics -Filter 'DisconnectDate -ne $null' | Select-Object DisplayName, TotalItemSize, DisconnectDate
                            

This cmdlet does not require any parameter replacement as it queries all databases for disconnected mailboxes.

Method 3: Getting mailbox size reports using Exchange Reporter Plus

1. Log in to Exchange Reporter Plus and go to Reports > Exchange Server > Mailboxes and click Mailbox Size under Size Reports.
2. Select the required Exchange Organization, choose the desired date to filter the data, and then click Apply.

Stay informed about growing mailbox sizes

Exchange Reporter Plus empowers administrators with deep visibility into mailbox sizes and storage trends across their Exchange environments. The tool is designed to help Exchange admins monitor usage and identify potential storage bottlenecks with comprehensive, exportable reports.

In summary, Exchange Reporter Plus offers comprehensive mailbox size reporting and analytics that enable administrators to monitor storage trends and identify potential risks. With its extensive range of detailed, exportable reports, you can gain clear insights into your Exchange environment’s mailbox storage usage from a single, intuitive console.

Important tips