foreach($server in get-transportservice){ `
  $server.Name; `
  Get-MessageTrackingLog `
    -Start "04/06/2016 00:00" `
    -End "04/08/2016 00:00" `
    -Server $server.Name `
    -Sender max.mustermann@contoso.com `
    -Recipients john.doe@someothercorp.com `
    -EventID "Deliver" `
    | ft}