I don’t have an on-premises Exchange server any more, but this code works for Exchange Online. I don’t recommend creating a complex set of piped cmdlets because it makes it awfully difficult to understand code (at times) and creates a support issue going forward.

$Report = [System.Collections.Generic.List[Object]]::new()
[array]$Mailboxes = Get-Mailbox -RecipientTypeDetails UserMailbox -ResultSize Unlimited | Sort-Object DisplayName
ForEach ($Mbx in $Mailboxes) {
$Stats = Get-MailboxStatistics -Identity $Mbx.Alias
[float]$MbxSizeGB = [math]::Round(($Stats.TotalItemSize.value.ToString().Split(“(“)[1].Split(” “)[0].Replace(“,”,””)/1024MB),2)
If ($MbxSizeGB -gt 50 ) {
$FolderStats = Get-MailboxFolderStatistics -Identity $Mbx.Alias -IncludeOldestAndNewestItems | `
Select-Object Name, OldestItemReceivedDate | Sort-Object OldestItemReceivedDate | `
Where-Object OldestItemReceiveddate -ne $null | Select-Object -First 1
$ReportLine = [PSCustomObject][Ordered]@{
Mailbox = $Mbx.displayName
‘Size GB’ = $MbxSizeGB
Folder = $FolderStats.name
‘Oldest item’ = $FolderStats.OldestItemReceivedDate
}
$Report.Add($ReportLine)
}
}

$Report | Out-GridView

This is what I have so far – Any help is much appreciated!
$mailboxes = @(Get-Mailbox -ResultSize Unlimited | Get-MailboxStatistics | Where-Object { $_.TotalItemSize -gt “50GB” } | Select DisplayName, @{expression={(Get-Recipient $_.DisplayName).OrganizationalUnit};name=”OrganizationalUnit”}, @{label=”TotalItemSize”;expression={[math]::Round(($_.TotalItemSize.value.ToString().Split(“(“)[1].Split(” “)[0].Replace(“,”,””)/1024MB),2)}})
$report = “C:\Reports\Exchange\Test.csv”
foreach ($mailbox in $mailboxes)
{
$inboxstats = Get-MailboxFolderStatistics $mailbox.DisplayName -IncludeOldestAndNewestItems | Select FolderName, OldestItemReceivedDate | Sort OldestItemReceivedDate | Where OldestItemReceiveddate -ne $null | Select-Object -First 1

$mbObj = New-Object PSObject
$mbObj | Add-Member -MemberType NoteProperty -Name “DisplayName” -Value $mailbox.DisplayName
$mbObj | Add-Member -MemberType NoteProperty -Name “OU” -Value $mailbox.OrganizationalUnit
$mbObj | Add-Member -MemberType NoteProperty -Name “TotalItemSize(GB)” -Value $mailbox.TotalItemSize
$mbObj | Add-Member -MemberType NoteProperty -Name “FolderName” -Value $inboxstats.Name
$mbObj | Add-Member -MemberType NoteProperty -Name “OldestItem” -Value $inboxstats.OldestItemReceivedDate
$report += $mbObj
}
$report

echo $mailbox.PRIMARYSMTPADDRESS
$inboxstats = Get-MailboxFolderStatistics $mailbox.PRIMARYSMTPADDRESS

Inactive mailboxes are inactive. The Get-MailboxStatistics cmdlet (or Get-ExoMailboxStatistics) doesn’t support inactive mailboxes.

Please export the user’s alias to a CSV file with the below CMD:

Get-Mailbox | ft Displayname, Alias >C:\Temp\userlist.csv

Then use the below CMD and get the contacts per user:

Import-Csv C:\Temp\userlist.csv | ForEach {Get-MailboxFolderStatistics -identity $_.Alias -FolderScope Contacts | Where {$_.FolderPath -eq “/Contacts”} | Select Name,FolderandSubFolderSize,ItemsinFolderandSubfolders } >C:\Temp\users_contacts.csv

Later you can merge the data in both the excel files to get the final report.

If you have a defined set of folders that you need to grab information for, you can use the Graph API to fetch the folders and then parse them to find the target set (like I do for the Inbox in https://office365itpros.com/2022/05/19/mailbox-folder-statistics/). After that, it’s a matter of straightforward PowerShell to grab the statistics for those folders. Using the Graph with PowerShell is much faster than trying to do this with Get-ExoMailboxFolderStatistics…

Is that script working with microsoft 365 today ?

Does anyone know a solution for me?

There are a number of users of exchange 2016 where the mailbox is too big.
I want to reduce this, and now i would like an output (*csv) which contains the senders (or domains) and the total mb’s of the senders.
I can’t so far, can anyone help?

Thank you in advance
Jarno