diff --git a/src/applications/config/controller/PhabricatorConfigEditController.php b/src/applications/config/controller/PhabricatorConfigEditController.php
index c3a277c087..78b9f96e0c 100644
--- a/src/applications/config/controller/PhabricatorConfigEditController.php
+++ b/src/applications/config/controller/PhabricatorConfigEditController.php
@@ -253,6 +253,7 @@ final class PhabricatorConfigEditController
         }
         break;
       case 'string':
+      case 'enum':
         $set_value = (string)$value;
         break;
       case 'list<string>':
@@ -328,6 +329,7 @@ final class PhabricatorConfigEditController
     switch ($type) {
       case 'int':
       case 'string':
+      case 'enum':
         return $value;
       case 'bool':
         return $value ? 'true' : 'false';
@@ -360,6 +362,15 @@ final class PhabricatorConfigEditController
               'false' => idx($option->getBoolOptions(), 1),
             ));
         break;
+      case 'enum':
+        $options = array_mergev(
+          array(
+            array('' => pht('(Use Default)')),
+            $option->getEnumOptions(),
+          ));
+        $control = id(new AphrontFormSelectControl())
+          ->setOptions($options);
+        break;
       case 'class':
         $symbols = id(new PhutilSymbolLoader())
           ->setType('class')
diff --git a/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php b/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php
index df678b79a1..d3becd3296 100644
--- a/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php
+++ b/src/applications/config/management/PhabricatorConfigManagementSetWorkflow.php
@@ -53,6 +53,7 @@ final class PhabricatorConfigManagementSetWorkflow
     switch ($type) {
       case 'string':
       case 'class':
+      case 'enum':
         $value = (string)$value;
         break;
       case 'int':
diff --git a/src/applications/config/option/PhabricatorConfigOption.php b/src/applications/config/option/PhabricatorConfigOption.php
index df3a780ab4..5d0b5a286f 100644
--- a/src/applications/config/option/PhabricatorConfigOption.php
+++ b/src/applications/config/option/PhabricatorConfigOption.php
@@ -10,6 +10,7 @@ final class PhabricatorConfigOption
   private $description;
   private $type;
   private $boolOptions;
+  private $enumOptions;
   private $group;
   private $examples;
   private $locked;
@@ -115,6 +116,20 @@ final class PhabricatorConfigOption
     );
   }
 
+  public function setEnumOptions(array $options) {
+    $this->enumOptions = $options;
+    return $this;
+  }
+
+  public function getEnumOptions() {
+    if ($this->enumOptions) {
+      return $this->enumOptions;
+    }
+
+    throw new Exception(
+      'Call setEnumOptions() before trying to access them!');
+  }
+
   public function setKey($key) {
     $this->key = $key;
     return $this;
diff --git a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
index b3c188f335..19437ffffe 100644
--- a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
+++ b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
@@ -317,10 +317,20 @@ EODOC
         ->setSummary(
           pht('Allow Phabricator to use a single mailbox for all replies.'))
         ->setDescription($single_description),
-      // TODO: 'enum'
-      $this->newOption('metamta.user-address-format', 'string', 'full')
+      $this->newOption('metamta.user-address-format', 'enum', 'full')
+        ->setEnumOptions(
+          array(
+            'short' => 'short',
+            'real' => 'real',
+            'full' => 'full',
+          ))
         ->setSummary(pht('Control how Phabricator renders user names in mail.'))
-        ->setDescription($address_description),
+        ->setDescription($address_description)
+        ->addExample('gwashington <gwashington@example.com>', 'short')
+        ->addExample('George Washington <gwashington@example.com>', 'real')
+        ->addExample(
+          'gwashington (George Washington) <gwashington@example.com>',
+          'full'),
     );
   }