diff --git a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
index 99d3f9962b..1e2eaa5680 100644
--- a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
+++ b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
@@ -190,6 +190,10 @@ final class PhabricatorExtraConfigSetupCheck extends PhabricatorSetupCheck {
       'The Differential revision list view age UI elements have been removed '.
       'to simplify the interface.');
 
+    $global_settings_reason = pht(
+      'The "Re: Prefix" and "Vary Subjects" settings are now configured '.
+      'in global settings.');
+
     $ancient_config += array(
       'phid.external-loaders' =>
         pht(
@@ -321,6 +325,9 @@ final class PhabricatorExtraConfigSetupCheck extends PhabricatorSetupCheck {
 
       'differential.days-fresh' => $stale_reason,
       'differential.days-stale' => $stale_reason,
+
+      'metamta.re-prefix' => $global_settings_reason,
+      'metamta.vary-subjects' => $global_settings_reason,
     );
 
     return $ancient_config;
diff --git a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
index 16bdb7e520..45604f6872 100644
--- a/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
+++ b/src/applications/config/option/PhabricatorMetaMTAConfigOptions.php
@@ -276,22 +276,6 @@ EODOC
           ))
         ->setSummary(pht('Show email preferences link in email.'))
         ->setDescription($email_preferences_description),
-      $this->newOption('metamta.re-prefix', 'bool', false)
-        ->setBoolOptions(
-          array(
-            pht('Force "Re:" Subject Prefix'),
-            pht('No "Re:" Subject Prefix'),
-          ))
-        ->setSummary(pht('Control "Re:" subject prefix, for Mail.app.'))
-        ->setDescription($re_prefix_description),
-      $this->newOption('metamta.vary-subjects', 'bool', true)
-        ->setBoolOptions(
-          array(
-            pht('Allow Varied Subjects'),
-            pht('Always Use the Same Thread Subject'),
-          ))
-        ->setSummary(pht('Control subject variance, for some mail clients.'))
-        ->setDescription($vary_subjects_description),
       $this->newOption('metamta.insecure-auth-with-reply-to', 'bool', false)
         ->setBoolOptions(
           array(
diff --git a/src/applications/metamta/storage/PhabricatorMetaMTAMail.php b/src/applications/metamta/storage/PhabricatorMetaMTAMail.php
index dcc14f0cc1..ceea3f0429 100644
--- a/src/applications/metamta/storage/PhabricatorMetaMTAMail.php
+++ b/src/applications/metamta/storage/PhabricatorMetaMTAMail.php
@@ -1131,27 +1131,16 @@ final class PhabricatorMetaMTAMail
   }
 
   private function shouldAddRePrefix(PhabricatorUserPreferences $preferences) {
-    $default_value = PhabricatorEnv::getEnvConfig('metamta.re-prefix');
-
-    $value = $preferences->getPreference(
+    $value = $preferences->getSettingValue(
       PhabricatorEmailRePrefixSetting::SETTINGKEY);
-    if ($value === null) {
-      return $default_value;
-    }
 
     return ($value == PhabricatorEmailRePrefixSetting::VALUE_RE_PREFIX);
   }
 
   private function shouldVarySubject(PhabricatorUserPreferences $preferences) {
-    $default_value = PhabricatorEnv::getEnvConfig('metamta.vary-subjects');
-
-    $value = $preferences->getPreference(
+    $value = $preferences->getSettingValue(
       PhabricatorEmailVarySubjectsSetting::SETTINGKEY);
 
-    if ($value === null) {
-      return $default_value;
-    }
-
     return ($value == PhabricatorEmailVarySubjectsSetting::VALUE_VARY_SUBJECTS);
   }
 
diff --git a/src/applications/settings/setting/PhabricatorEmailRePrefixSetting.php b/src/applications/settings/setting/PhabricatorEmailRePrefixSetting.php
index 2a2f63b461..7b04ef80c3 100644
--- a/src/applications/settings/setting/PhabricatorEmailRePrefixSetting.php
+++ b/src/applications/settings/setting/PhabricatorEmailRePrefixSetting.php
@@ -39,7 +39,7 @@ final class PhabricatorEmailRePrefixSetting
   }
 
   public function getSettingDefaultValue() {
-    return self::VALUE_RE_PREFIX;
+    return self::VALUE_NO_PREFIX;
   }
 
   protected function getSelectOptions() {