Export Exchange Online mailbox and archive stats to CSV

If you’re like me, you’ve written variations of this script a hundred times. I decided to finally blog it and put it on git so that I could refer back. This script will get all exchange online mailboxes, check if an archive exists then dump all relevant information to CSV. It helps to know the quota of a mailbox and archive (dependent on your 365 license type), as well as the current usage, item count and if auto expanding archive is enabled. The script will report progress to the console as it goes letting you know what mailbox it’s currently processing and how many are left to process. Enjoy.

# Establish output path
$OutputPath = "$env:TEMP\$(Get-date -Format 'yyyyMMddhhmmss')_mailbox_report.csv"

# Establish result array variable

# Get all mailboxes
$mailboxes = Get-Mailbox -ResultSize Unlimited

# Get total mailboxes and establish counter variable
$totalmbx = $mailboxes.Count
$i = 0 

# Loop through each mailbox and perform actions
$mailboxes | ForEach-Object {
    # Increment counter
    # Add current mailbox to $mbx variable
    $mbx = $_
    # Reset variables for next loop
    $mba = $null
    $mbs = $null
    $mbasize = $null
    $mbssize = $null
    $MailboxAllocationInGB = $null
    $ArchiveAllocationInGB = $null
    # Write progress to host
    Write-Host "Processing $mbx" "$i out of $totalmbx completed"
    # Check if archive enabled, if so, get archive stats
    if ($mbx.ArchiveName){
        $mba = Get-MailboxStatistics -Archive $mbx.UserPrincipalName
        # Format archive size to GB with 2 decimal places
        if ($mba.TotalItemSize -ne $null){
            $mbasize = [math]::Round(($mba.TotalItemSize.ToString().Split('(')[1].Split(' ')[0].Replace(',','')/1GB),2)
            $mbasize = 0 

    # Get mailbox stats
    $mbs = Get-MailboxStatistics $mbx.UserPrincipalName
        # Format mailbox size to GB with 2 decimal places
        if ($mbs.TotalItemSize -ne $null){
            $mbssize = [math]::Round(($mbs.TotalItemSize.ToString().Split('(')[1].Split(' ')[0].Replace(',','')/1GB),2)
            $mbssize = 0 

    # Get archive allocation (quota) and trim everything but the size in GB
    if ($mbx.ArchiveName){
        $ArchiveAllocationInGB = $mbx.ArchiveQuota.Split('G')
        $ArchiveAllocationInGB = $ArchiveAllocationInGB[0]
    # Get mailbox allocation (quota) and trim everything but the size in GB
    $MailboxAllocationInGB = $mbx.ProhibitSendReceiveQuota.Split('G')
    $MailboxAllocationInGB = $MailboxAllocationInGB[0]

    # Create PSObject and store all relevant information for export
    $Result += New-Object -TypeName PSObject -Property $([ordered]@{ 
        UserName = $mbx.DisplayName
        UserPrincipalName = $mbx.UserPrincipalName
        MailboxType = $mbx.RecipientTypeDetails
        MailboxAllocationInGB = $MailboxAllocationInGB
        MailboxSizeInGB = $mbssize
        MailboxItemCount = if ($mbs.ItemCount) {$mbs.ItemCount} Else { $null}
        ArchiveEnabled = if ($mbx.ArchiveName) {"Enabled"} Else { "Disabled"}
        ArchiveName = $mbx.ArchiveName
        ArchiveAllocationInGB = if ($mbx.ArchiveName) {$ArchiveAllocationInGB} Else { $null} 
        ArchiveSizeInGB = $mbasize
        ArchiveItemCount = if ($mba.ItemCount) {$mba.ItemCount} Else { $null}
        AutoExpandingArchiveEnabled = $mbx.AutoExpandingArchiveEnabled
# Export results to CSV
$Result | Export-CSV $OutputPath -NoTypeInformation -Encoding UTF8
Write-Host "Output csv file is located here: `n `n $OutputPath `n" -ForegroundColor Yellow

Code also on my github here.

Thanks for reading – Jesse

Office 365 Trial

For anyone wanting to test Office 365 and associated technologies, you can easily spin up a free trial, without a credit card for evaluating and seeing what 365 has to offer.

To get started, head over to outlook.com and create a free account. In this example, i’m using the address trial-365-2021@outlook.com

After you have your outlook.com account, browse to the following portal.office.com link which is the standing offer for a 30 day free trial of Office 365 E3 that includes 25 licenses.

Go through the wizard and fill in your details. You’ll need a legitimate phone number to verify you are a person and not a bot. You’ll create your business identity and proceed to create an admin login.

As you can see, my trial has been created and a confirmation email sent to my test outlook.com email address.

Now, you can jump over to https://portal.office.com/AdminPortal/ and login with your trial admin account. From here, jump into licenses and you’ll see your 30 days of Office 365 E3, which includes fully routable mail to your <domain>.onmicrosoft.com address.

From time to time, Microsoft offer other trials that you can add to your existing subscription. For example, at the moment, you can add PowerBI Premium or Defender for Office 365 trials. From the admin portal, browse to Billing –> Purchase Services –> Search –> ‘Trial’ and see what is available.

Now that you have your trial, you can test Exchange Online, SharePoint Online, Yammer, Teams and OneDrive – not to mention Azure AD and all the identity features that come along with it.

Good luck with your 365 trial!

Thanks for reading -Jesse