private function buildHeaderProperties(PhabricatorMetaMTAMail $mail)
{
$viewer = $this->getViewer();
$properties = id(new PHUIPropertyListView())->setUser($viewer)->setStacked(true);
$headers = $mail->getDeliveredHeaders();
if ($headers === null) {
$headers = $mail->generateHeaders();
}
// Sort headers by name.
$headers = isort($headers, 0);
foreach ($headers as $header) {
list($key, $value) = $header;
$properties->addProperty($key, $value);
}
return $properties;
}