diff --git a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
--- a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
+++ b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
@@ -188,7 +188,7 @@
       pht('Configuring Outbound Email')));
 
     return array(
-      $this->newOption('cluster.mailers', 'cluster.mailers', null)
+      $this->newOption('cluster.mailers', 'cluster.mailers', array())
         ->setHidden(true)
         ->setDescription($mailers_description),
       $this->newOption('metamta.default-address', 'string', null)
diff --git a/src/docs/user/configuration/configuring_outbound_email.diviner b/src/docs/user/configuration/configuring_outbound_email.diviner
--- a/src/docs/user/configuration/configuring_outbound_email.diviner
+++ b/src/docs/user/configuration/configuring_outbound_email.diviner
@@ -247,7 +247,7 @@
 configure.
 
 
-Mailer: STMP
+Mailer: SMTP
 ============
 
 You can use this adapter to send mail via an external SMTP server, like Gmail.