Get large mailbox items

Connect-MgGraph -App $AppId -TenantId $TenantId -CertificateThumbprint $CertThumbprint -NoWelcome

param(
    [string] $TenantId = "",
    [string] $AppId = "",
    [string] $CertThumbPrint = "",
    [string] $StartDate = (Get-Date $Start -ErrorAction Stop).ToString('s') + "Z,
    [string] $EndDate = (Get-Date $End -ErrorAction Stop).ToString('s') + "Z
)
 
[CmdletBinding()]
param(
    [Parameter(Mandatory)]
    [string] $Mailbox,
 
    [Parameter(Mandatory)]
    [int32] $Threshold,
 
    [Parameter(Mandatory)]
    [string] $Start,
 
    [Parameter(Mandatory)]
    [string] $End
)
 
# Change these values to match your app registration and your tenant!!!
$CertThumbprint = "0CF6CE3F3548FD73E7AC8CF20226ED447E125C71"
Connect-MgGraph -App $AppId -TenantId $TenantId -CertificateThumbprint $CertThumbprint -NoWelcome
 
Try {
} Catch {
    Write-Host "$Start is not a valid date" -ForegroundColor Red
    Break
}
Try {
} Catch {
    Write-Host "$End is not a valid date" -ForegroundColor Red
    Break
}
 
# Attempt to find account for the mailbox to check that it exists
Try {
    $User = Get-MgUser -UserId $Mailbox -ErrorAction Stop
} Catch {
    Write-Host "Cannot find mailbox for $Mailbox" -ForegroundColor Red
    Break
}
 
# Run server-side filter to find large items in the target folder within the date range
Try {
    [array]$LargeItems = Get-MgUserMailFolderMessage -UserId $User.Id -MailFolderId Inbox -All `
     -PageSize 500 -Property Sender,ReceivedDateTime,BodyPreview,Subject,ToRecipients `
     -Filter "(hasattachments eq true and receivedDateTime ge $startdate and receivedDateTime le $enddate) AND singleValueExtendedProperties/any(ep:ep/id eq 'Integer 0x0E08' and cast(ep/value, 'Edm.Int32') gt $Threshold)" -expand "singleValueExtendedProperties(`$filter=(id eq 'Integer 0x0e08'))" -ErrorAction Stop
} Catch {
    Write-Host "Error retrieving mailbox items for $Mailbox. $_" -ForegroundColor Red
    Break
}
 
If (!($LargeItems)) {
    Write-Host "No items larger than $Threshold bytes found in the Inbox of $Mailbox" -ForegroundColor Yellow
    Break
}
 
$Report = [System.Collections.Generic.List[Object]]::new()
# Client-side size check
$LargeItems | ForEach-Object {
    $Size = [int64]$_.SingleValueExtendedProperties[0].Value
    If ($Size -gt $Threshold) {
        $ReportLine = [PSCustomObject][Ordered]@{
            Subject          = $_.Subject
            From             = $_.Sender.EmailAddress.Address
            ReceivedDateTime = $_.ReceivedDateTime
            SizeMB           = [math]::Round($Size / 1MB, 2)
            Id               = $_.Id
        }
        $Report.Add($ReportLine)
    }
}
$Report = $Report | Sort-Object {$_.ReceivedDateTime -as [datetime]} -Descending
 
Write-Host ""
Write-Host ("{0} item(s) largher than the threshold of {1} bytes were found in {2}'s mailbox" -f $LargeItems.Count, $Threshold, $User.DisplayName) -ForegroundColor Cyan
Write-Host "------------------------------------------------------------------------------------------" -ForegroundColor Cyan
 
$Report | Select-Object Subject,From,ReceivedDateTime,SizeMB | Format-Table -AutoSize
$Report | Sort-Object SizeMB -Descending | Out-GridView -Title "Large Emails in Inbox over $($Threshold / 1MB) MB"