diff --git a/src/applications/metamta/management/PhabricatorMailManagementShowOutboundWorkflow.php b/src/applications/metamta/management/PhabricatorMailManagementShowOutboundWorkflow.php
--- a/src/applications/metamta/management/PhabricatorMailManagementShowOutboundWorkflow.php
+++ b/src/applications/metamta/management/PhabricatorMailManagementShowOutboundWorkflow.php
@@ -203,7 +203,7 @@
 
       $info[] = null;
       $info[] = $this->newSectionHeader(pht('HTML BODY'));
-      if (strlen($message->getHTMLBody())) {
+      if (phutil_nonempty_string($message->getHTMLBody())) {
         $info[] = $message->getHTMLBody();
         $info[] = null;
       } else {