Public/Graph/Get-GraphMailFolderRecoverableItems.ps1

function Get-GraphMailFolderRecoverableItems {
    [CmdletBinding()]
    param (
        [Parameter(ValueFromPipeline)]
        $UserPrincipalName
    )
    process {
        $Script:tree = @{ 'root' = [System.Collections.Generic.List[PSObject]]::new() }

        foreach ($UPN in $UserPrincipalName) {
            if ([datetime]::UtcNow -ge $Script:TimeToRefresh) { Connect-PoshGraphRefresh }
            $RestSplat = @{
                Uri     = "https://graph.microsoft.com/beta/users/{0}/mailfolders/root/childFolders?`$top=1000" -f $UPN.UserPrincipalName
                Headers = @{ "Authorization" = "Bearer $Token" }
                Method  = 'Get'
            }
            try {
                Write-Host "`r`nMailbox (RecoverableItems): $($UPN.UserPrincipalName) " -ForegroundColor Green -NoNewline
                $FolderList = ((Invoke-RestMethod @RestSplat -Verbose:$false).value).where{ $_.wellKnownName -like 'RecoverableItems*' }
                foreach ($Folder in $FolderList) {
                    $tree['root'].Add(@{
                            DisplayName       = $UPN.DisplayName
                            Mail              = $UPN.Mail
                            UserPrincipalName = $UPN.UserPrincipalName
                            Folder            = $Folder.DisplayName
                            ChildFolderCount  = $Folder.ChildFolderCount
                            unreadItemCount   = $Folder.unreaditemCount
                            totalItemCount    = $Folder.totalItemCount
                            wellKnownName     = $Folder.wellKnownName
                            ParentFolderId    = 'root'
                            Id                = $Folder.Id
                        })
                    if ($Folder.ChildFolderCount -ge 1) {
                        $ChildSplat = @{
                            DisplayName       = $UPN.DisplayName
                            Mail              = $UPN.Mail
                            UserPrincipalName = $UPN.UserPrincipalName
                            Tree              = $tree
                        }
                        $Folder | Get-GraphMailFolderChild @ChildSplat
                    }
                }
            }
            catch { Write-Host "Not Found" -ForegroundColor Red -NoNewline }
        }
        Get-TreePrintout -Tree $tree -id 'root'
    }
}