diff --git a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
index c2418370a6..67b17c9069 100644
--- a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
+++ b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
@@ -260,10 +260,10 @@ final class PhabricatorMetaMTAReceivedMail extends PhabricatorMetaMTADAO {
       $receiver->setPriority(ManiphestTaskPriority::PRIORITY_TRIAGE);
 
       $editor = new ManiphestTransactionEditor();
-      $editor->setActor($user);
+      $editor->setActor($user->getPhabricatorUser());
       $handler = $editor->buildReplyHandler($receiver);
 
-      $handler->setActor($user);
+      $handler->setActor($user->getPhabricatorUser());
       $handler->setExcludeMailRecipientPHIDs(
       $this->loadExcludeMailRecipientPHIDs());
       $handler->processEmail($this);
diff --git a/src/applications/people/storage/PhabricatorExternalAccount.php b/src/applications/people/storage/PhabricatorExternalAccount.php
index cffffdb482..0f0e9ef92b 100644
--- a/src/applications/people/storage/PhabricatorExternalAccount.php
+++ b/src/applications/people/storage/PhabricatorExternalAccount.php
@@ -20,4 +20,11 @@ final class PhabricatorExternalAccount extends PhabricatorUserDAO {
     ) + parent::getConfiguration();
   }
 
+  public function getPhabricatorUser() {
+    $tmp_usr = id(new PhabricatorUser())
+      ->makeEphemeral()
+      ->setPHID($this->getPHID());
+    return $tmp_usr;
+  }
+
 }
diff --git a/src/applications/phid/handle/PhabricatorObjectHandleData.php b/src/applications/phid/handle/PhabricatorObjectHandleData.php
index 2a9743a1d1..c018e65a1e 100644
--- a/src/applications/phid/handle/PhabricatorObjectHandleData.php
+++ b/src/applications/phid/handle/PhabricatorObjectHandleData.php
@@ -205,6 +205,13 @@ final class PhabricatorObjectHandleData {
           ->execute();
         return mpull($vars, null, 'getPHID');
 
+      case PhabricatorPHIDConstants::PHID_TYPE_XUSR:
+        $xusr_dao = new PhabricatorExternalAccount();
+        $xusrs = $xusr_dao->loadAllWhere(
+          'phid in (%Ls)',
+          $phids);
+        return mpull($xusrs, null, 'getPHID');
+
     }
   }
 
@@ -681,6 +688,23 @@ final class PhabricatorObjectHandleData {
           }
           break;
 
+        case PhabricatorPHIDConstants::PHID_TYPE_XUSR:
+          foreach ($phids as $phid) {
+            $handle = new PhabricatorObjectHandle();
+            $handle->setPHID($phid);
+            $handle->setType($type);
+            if (empty($objects[$phid])) {
+              $handle->setName('Unknown Display Name');
+            } else {
+              $xusr = $objects[$phid];
+              $display_name = $xusr->getDisplayName();
+              $handle->setName($display_name);
+              $handle->setFullName($display_name.' (External User)');
+            }
+            $handles[$phid] = $handle;
+          }
+          break;
+
         default:
           $loader = null;
           if (isset($external_loaders[$type])) {