diff --git a/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php b/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php
index 1dc68fe93b..d36682e9f8 100644
--- a/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php
+++ b/src/applications/metamta/management/PhabricatorMailManagementSendTestWorkflow.php
@@ -1,153 +1,163 @@
 <?php
 
 final class PhabricatorMailManagementSendTestWorkflow
   extends PhabricatorMailManagementWorkflow {
 
   protected function didConstruct() {
     $this
       ->setName('send-test')
       ->setSynopsis(
         pht(
           'Simulate sending mail. This may be useful to test your mail '.
           'configuration, or while developing new mail adapters.'))
       ->setExamples(
         '**send-test** --to alincoln --subject hi < body.txt')
       ->setArguments(
         array(
           array(
             'name'    => 'from',
             'param'   => 'user',
             'help'    => 'Send mail from the specified user.',
           ),
           array(
             'name'    => 'to',
             'param'   => 'user',
             'help'    => 'Send mail "To:" the specified users.',
             'repeat'  => true,
           ),
           array(
             'name'    => 'cc',
             'param'   => 'user',
             'help'    => 'Send mail which "Cc:"s the specified users.',
             'repeat'  => true,
           ),
           array(
             'name'    => 'subject',
             'param'   => 'text',
             'help'    => 'Use the provided subject.',
           ),
           array(
             'name'    => 'tag',
             'param'   => 'text',
             'help'    => 'Add the given mail tags.',
             'repeat'  => true,
           ),
           array(
             'name'    => 'attach',
             'param'   => 'file',
             'help'    => 'Attach a file.',
             'repeat'  => true,
           ),
           array(
             'name'    => 'html',
             'help'    => 'Send as HTML mail.',
           ),
           array(
             'name'    => 'bulk',
             'help'    => 'Send with bulk headers.',
           ),
         ));
   }
 
   public function execute(PhutilArgumentParser $args) {
     $console = PhutilConsole::getConsole();
     $viewer = $this->getViewer();
 
     $from = $args->getArg('from');
     if ($from) {
       $user = id(new PhabricatorPeopleQuery())
         ->setViewer($viewer)
         ->withUsernames(array($from))
         ->executeOne();
       if (!$user) {
         throw new PhutilArgumentUsageException(
           pht("No such user '%s' exists.", $from));
       }
       $from = $user;
     }
 
     $tos = $args->getArg('to');
     $ccs = $args->getArg('cc');
 
+    if (!$tos && !$ccs) {
+      throw new PhutilArgumentUsageException(
+        pht(
+          'Specify one or more users to send mail to with `--to` and '.
+          '`--cc`.'));
+    }
+
     $names = array_merge($tos, $ccs);
     $users = id(new PhabricatorPeopleQuery())
       ->setViewer($viewer)
       ->withUsernames($names)
       ->execute();
     $users = mpull($users, null, 'getUsername');
 
     foreach ($tos as $key => $username) {
       if (empty($users[$username])) {
         throw new PhutilArgumentUsageException(
           pht("No such user '%s' exists.", $username));
       }
       $tos[$key] = $users[$username]->getPHID();
     }
 
     foreach ($ccs as $key => $username) {
       if (empty($users[$username])) {
         throw new PhutilArgumentUsageException(
           pht("No such user '%s' exists.", $username));
       }
       $ccs[$key] = $users[$username]->getPHID();
     }
 
     $subject = $args->getArg('subject');
+    if ($subject === null) {
+      $subject = pht('No Subject');
+    }
+
     $tags = $args->getArg('tag');
     $attach = $args->getArg('attach');
     $is_bulk = $args->getArg('bulk');
 
     $console->writeErr("%s\n", pht('Reading message body from stdin...'));
     $body = file_get_contents('php://stdin');
 
-
     $mail = id(new PhabricatorMetaMTAMail())
       ->addTos($tos)
       ->addCCs($ccs)
       ->setSubject($subject)
       ->setBody($body)
       ->setIsBulk($is_bulk)
       ->setMailTags($tags);
 
     if ($args->getArg('html')) {
       $mail->setBody(
         pht('(This is a placeholder plaintext email body for a test message '.
             'sent with --html.)'));
 
       $mail->setHTMLBody($body);
     } else {
       $mail->setBody($body);
     }
 
     if ($from) {
       $mail->setFrom($from->getPHID());
     }
 
     foreach ($attach as $attachment) {
       $data = Filesystem::readFile($attachment);
       $name = basename($attachment);
       $mime = Filesystem::getMimeType($attachment);
       $file = new PhabricatorMetaMTAAttachment($data, $name, $mime);
       $mail->addAttachment($file);
     }
 
     PhabricatorWorker::setRunAllTasksInProcess(true);
     $mail->save();
 
     $console->writeErr(
       "%s\n\n    phabricator/ $ ./bin/mail show-outbound --id %d\n\n",
       pht('Mail sent! You can view details by running this command:'),
       $mail->getID());
   }
 
 }