diff --git a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
--- a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
+++ b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
@@ -524,7 +524,7 @@
   public function newFromAddress() {
     $raw_from = $this->getHeader('From');
 
-    if (strlen($raw_from)) {
+    if (phutil_nonempty_string($raw_from)) {
       return new PhutilEmailAddress($raw_from);
     }