diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -341,7 +341,6 @@
     'ConduitWildParameterType' => 'applications/conduit/parametertype/ConduitWildParameterType.php',
     'ConpherenceColumnViewController' => 'applications/conpherence/controller/ConpherenceColumnViewController.php',
     'ConpherenceConduitAPIMethod' => 'applications/conpherence/conduit/ConpherenceConduitAPIMethod.php',
-    'ConpherenceConfigOptions' => 'applications/conpherence/config/ConpherenceConfigOptions.php',
     'ConpherenceConstants' => 'applications/conpherence/constants/ConpherenceConstants.php',
     'ConpherenceController' => 'applications/conpherence/controller/ConpherenceController.php',
     'ConpherenceCreateThreadConduitAPIMethod' => 'applications/conpherence/conduit/ConpherenceCreateThreadConduitAPIMethod.php',
@@ -3333,7 +3332,6 @@
     'PhabricatorLDAPAuthProvider' => 'applications/auth/provider/PhabricatorLDAPAuthProvider.php',
     'PhabricatorLabelProfileMenuItem' => 'applications/search/menuitem/PhabricatorLabelProfileMenuItem.php',
     'PhabricatorLegalpadApplication' => 'applications/legalpad/application/PhabricatorLegalpadApplication.php',
-    'PhabricatorLegalpadConfigOptions' => 'applications/legalpad/config/PhabricatorLegalpadConfigOptions.php',
     'PhabricatorLegalpadDocumentPHIDType' => 'applications/legalpad/phid/PhabricatorLegalpadDocumentPHIDType.php',
     'PhabricatorLegalpadSignaturePolicyRule' => 'applications/legalpad/policyrule/PhabricatorLegalpadSignaturePolicyRule.php',
     'PhabricatorLibraryTestCase' => '__tests__/PhabricatorLibraryTestCase.php',
@@ -3362,7 +3360,6 @@
     'PhabricatorMacroAudioBehaviorTransaction' => 'applications/macro/xaction/PhabricatorMacroAudioBehaviorTransaction.php',
     'PhabricatorMacroAudioController' => 'applications/macro/controller/PhabricatorMacroAudioController.php',
     'PhabricatorMacroAudioTransaction' => 'applications/macro/xaction/PhabricatorMacroAudioTransaction.php',
-    'PhabricatorMacroConfigOptions' => 'applications/macro/config/PhabricatorMacroConfigOptions.php',
     'PhabricatorMacroController' => 'applications/macro/controller/PhabricatorMacroController.php',
     'PhabricatorMacroDatasource' => 'applications/macro/typeahead/PhabricatorMacroDatasource.php',
     'PhabricatorMacroDisableController' => 'applications/macro/controller/PhabricatorMacroDisableController.php',
@@ -3766,7 +3763,6 @@
     'PhabricatorPaste' => 'applications/paste/storage/PhabricatorPaste.php',
     'PhabricatorPasteApplication' => 'applications/paste/application/PhabricatorPasteApplication.php',
     'PhabricatorPasteArchiveController' => 'applications/paste/controller/PhabricatorPasteArchiveController.php',
-    'PhabricatorPasteConfigOptions' => 'applications/paste/config/PhabricatorPasteConfigOptions.php',
     'PhabricatorPasteContentSearchEngineAttachment' => 'applications/paste/engineextension/PhabricatorPasteContentSearchEngineAttachment.php',
     'PhabricatorPasteContentTransaction' => 'applications/paste/xaction/PhabricatorPasteContentTransaction.php',
     'PhabricatorPasteController' => 'applications/paste/controller/PhabricatorPasteController.php',
@@ -3851,7 +3847,6 @@
     'PhabricatorPhamePostPHIDType' => 'applications/phame/phid/PhabricatorPhamePostPHIDType.php',
     'PhabricatorPhluxApplication' => 'applications/phlux/application/PhabricatorPhluxApplication.php',
     'PhabricatorPholioApplication' => 'applications/pholio/application/PhabricatorPholioApplication.php',
-    'PhabricatorPholioConfigOptions' => 'applications/pholio/config/PhabricatorPholioConfigOptions.php',
     'PhabricatorPholioMockTestDataGenerator' => 'applications/pholio/lipsum/PhabricatorPholioMockTestDataGenerator.php',
     'PhabricatorPhoneNumber' => 'applications/metamta/message/PhabricatorPhoneNumber.php',
     'PhabricatorPhortuneApplication' => 'applications/phortune/application/PhabricatorPhortuneApplication.php',
@@ -3862,7 +3857,6 @@
     'PhabricatorPhragmentApplication' => 'applications/phragment/application/PhabricatorPhragmentApplication.php',
     'PhabricatorPhrequentApplication' => 'applications/phrequent/application/PhabricatorPhrequentApplication.php',
     'PhabricatorPhrictionApplication' => 'applications/phriction/application/PhabricatorPhrictionApplication.php',
-    'PhabricatorPhrictionConfigOptions' => 'applications/phriction/config/PhabricatorPhrictionConfigOptions.php',
     'PhabricatorPhurlApplication' => 'applications/phurl/application/PhabricatorPhurlApplication.php',
     'PhabricatorPhurlConfigOptions' => 'applications/config/option/PhabricatorPhurlConfigOptions.php',
     'PhabricatorPhurlController' => 'applications/phurl/controller/PhabricatorPhurlController.php',
@@ -5743,7 +5737,6 @@
     'ConduitWildParameterType' => 'ConduitParameterType',
     'ConpherenceColumnViewController' => 'ConpherenceController',
     'ConpherenceConduitAPIMethod' => 'ConduitAPIMethod',
-    'ConpherenceConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'ConpherenceConstants' => 'Phobject',
     'ConpherenceController' => 'PhabricatorController',
     'ConpherenceCreateThreadConduitAPIMethod' => 'ConpherenceConduitAPIMethod',
@@ -9172,7 +9165,6 @@
     'PhabricatorLDAPAuthProvider' => 'PhabricatorAuthProvider',
     'PhabricatorLabelProfileMenuItem' => 'PhabricatorProfileMenuItem',
     'PhabricatorLegalpadApplication' => 'PhabricatorApplication',
-    'PhabricatorLegalpadConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorLegalpadDocumentPHIDType' => 'PhabricatorPHIDType',
     'PhabricatorLegalpadSignaturePolicyRule' => 'PhabricatorPolicyRule',
     'PhabricatorLibraryTestCase' => 'PhutilLibraryTestCase',
@@ -9201,7 +9193,6 @@
     'PhabricatorMacroAudioBehaviorTransaction' => 'PhabricatorMacroTransactionType',
     'PhabricatorMacroAudioController' => 'PhabricatorMacroController',
     'PhabricatorMacroAudioTransaction' => 'PhabricatorMacroTransactionType',
-    'PhabricatorMacroConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorMacroController' => 'PhabricatorController',
     'PhabricatorMacroDatasource' => 'PhabricatorTypeaheadDatasource',
     'PhabricatorMacroDisableController' => 'PhabricatorMacroController',
@@ -9688,7 +9679,6 @@
     ),
     'PhabricatorPasteApplication' => 'PhabricatorApplication',
     'PhabricatorPasteArchiveController' => 'PhabricatorPasteController',
-    'PhabricatorPasteConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorPasteContentSearchEngineAttachment' => 'PhabricatorSearchEngineAttachment',
     'PhabricatorPasteContentTransaction' => 'PhabricatorPasteTransactionType',
     'PhabricatorPasteController' => 'PhabricatorController',
@@ -9773,7 +9763,6 @@
     'PhabricatorPhamePostPHIDType' => 'PhabricatorPHIDType',
     'PhabricatorPhluxApplication' => 'PhabricatorApplication',
     'PhabricatorPholioApplication' => 'PhabricatorApplication',
-    'PhabricatorPholioConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorPholioMockTestDataGenerator' => 'PhabricatorTestDataGenerator',
     'PhabricatorPhoneNumber' => 'Phobject',
     'PhabricatorPhortuneApplication' => 'PhabricatorApplication',
@@ -9784,7 +9773,6 @@
     'PhabricatorPhragmentApplication' => 'PhabricatorApplication',
     'PhabricatorPhrequentApplication' => 'PhabricatorApplication',
     'PhabricatorPhrictionApplication' => 'PhabricatorApplication',
-    'PhabricatorPhrictionConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorPhurlApplication' => 'PhabricatorApplication',
     'PhabricatorPhurlConfigOptions' => 'PhabricatorApplicationConfigOptions',
     'PhabricatorPhurlController' => 'PhabricatorController',
diff --git a/src/applications/audit/editor/PhabricatorAuditEditor.php b/src/applications/audit/editor/PhabricatorAuditEditor.php
--- a/src/applications/audit/editor/PhabricatorAuditEditor.php
+++ b/src/applications/audit/editor/PhabricatorAuditEditor.php
@@ -437,7 +437,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.diffusion.subject-prefix');
+    return pht('[Diffusion]');
   }
 
   protected function getMailThreadID(PhabricatorLiskDAO $object) {
diff --git a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
--- a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
+++ b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
@@ -203,6 +203,11 @@
     $mailers_reason = pht(
       'Inbound and outbound mail is now configured with "cluster.mailers".');
 
+    $prefix_reason = pht(
+      'Per-application mail subject prefix customization is no longer '.
+      'directly supported. Prefixes and other strings may be customized with '.
+      '"translation.override".');
+
     $ancient_config += array(
       'phid.external-loaders' =>
         pht(
@@ -398,6 +403,19 @@
       'phabricator.allow-email-users' => pht(
         'Public email is now accepted if the associated address has a '.
         'default author, and rejected otherwise.'),
+
+      'metamta.conpherence.subject-prefix' => $prefix_reason,
+      'metamta.differential.subject-prefix' => $prefix_reason,
+      'metamta.diffusion.subject-prefix' => $prefix_reason,
+      'metamta.files.subject-prefix' => $prefix_reason,
+      'metamta.legalpad.subject-prefix' => $prefix_reason,
+      'metamta.macro.subject-prefix' => $prefix_reason,
+      'metamta.maniphest.subject-prefix' => $prefix_reason,
+      'metamta.package.subject-prefix' => $prefix_reason,
+      'metamta.paste.subject-prefix' => $prefix_reason,
+      'metamta.pholio.subject-prefix' => $prefix_reason,
+      'metamta.phriction.subject-prefix' => $prefix_reason,
+
     );
 
     return $ancient_config;
diff --git a/src/applications/conpherence/config/ConpherenceConfigOptions.php b/src/applications/conpherence/config/ConpherenceConfigOptions.php
deleted file mode 100644
--- a/src/applications/conpherence/config/ConpherenceConfigOptions.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-final class ConpherenceConfigOptions
-  extends PhabricatorApplicationConfigOptions {
-
-  public function getName() {
-    return pht('Conpherence');
-  }
-
-  public function getDescription() {
-    return pht('Configure Conpherence messaging.');
-  }
-
-  public function getIcon() {
-    return 'fa-comments';
-  }
-
-  public function getGroup() {
-    return 'apps';
-  }
-
-  public function getOptions() {
-    return array(
-      $this->newOption(
-        'metamta.conpherence.subject-prefix',
-        'string',
-        '[Conpherence]')
-        ->setDescription(pht('Subject prefix for Conpherence mail.')),
-    );
-  }
-
-}
diff --git a/src/applications/conpherence/editor/ConpherenceEditor.php b/src/applications/conpherence/editor/ConpherenceEditor.php
--- a/src/applications/conpherence/editor/ConpherenceEditor.php
+++ b/src/applications/conpherence/editor/ConpherenceEditor.php
@@ -239,7 +239,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.conpherence.subject-prefix');
+    return pht('[Conpherence]');
   }
 
   protected function supportsSearch() {
diff --git a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
--- a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
+++ b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
@@ -228,11 +228,6 @@
             "\n\n".
             'This sort of workflow is very unusual. Very few installs should '.
             'need to change this option.')),
-      $this->newOption(
-        'metamta.differential.subject-prefix',
-        'string',
-        '[Differential]')
-        ->setDescription(pht('Subject prefix for Differential mail.')),
       $this->newOption(
         'metamta.differential.attach-patches',
         'bool',
diff --git a/src/applications/differential/doorkeeper/DifferentialDoorkeeperRevisionFeedStoryPublisher.php b/src/applications/differential/doorkeeper/DifferentialDoorkeeperRevisionFeedStoryPublisher.php
--- a/src/applications/differential/doorkeeper/DifferentialDoorkeeperRevisionFeedStoryPublisher.php
+++ b/src/applications/differential/doorkeeper/DifferentialDoorkeeperRevisionFeedStoryPublisher.php
@@ -81,8 +81,7 @@
   }
 
   private function getTitlePrefix(DifferentialRevision $revision) {
-    $prefix_key = 'metamta.differential.subject-prefix';
-    return PhabricatorEnv::getEnvConfig($prefix_key);
+    return pht('[Differential]');
   }
 
 }
diff --git a/src/applications/differential/editor/DifferentialTransactionEditor.php b/src/applications/differential/editor/DifferentialTransactionEditor.php
--- a/src/applications/differential/editor/DifferentialTransactionEditor.php
+++ b/src/applications/differential/editor/DifferentialTransactionEditor.php
@@ -563,7 +563,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.differential.subject-prefix');
+    return pht('[Differential]');
   }
 
   protected function getMailThreadID(PhabricatorLiskDAO $object) {
diff --git a/src/applications/differential/mail/DifferentialCreateMailReceiver.php b/src/applications/differential/mail/DifferentialCreateMailReceiver.php
--- a/src/applications/differential/mail/DifferentialCreateMailReceiver.php
+++ b/src/applications/differential/mail/DifferentialCreateMailReceiver.php
@@ -69,8 +69,7 @@
       }
     }
 
-    $subject_prefix =
-      PhabricatorEnv::getEnvConfig('metamta.differential.subject-prefix');
+    $subject_prefix = pht('[Differential]');
     if (count($diffs)) {
       $subject = pht(
         'You successfully created %d diff(s).',
diff --git a/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php b/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php
--- a/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php
+++ b/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php
@@ -37,11 +37,6 @@
     }
 
     return array(
-      $this->newOption(
-        'metamta.diffusion.subject-prefix',
-        'string',
-        '[Diffusion]')
-        ->setDescription(pht('Subject prefix for Diffusion mail.')),
       $this->newOption(
         'metamta.diffusion.attach-patches',
         'bool',
diff --git a/src/applications/diffusion/doorkeeper/DiffusionDoorkeeperCommitFeedStoryPublisher.php b/src/applications/diffusion/doorkeeper/DiffusionDoorkeeperCommitFeedStoryPublisher.php
--- a/src/applications/diffusion/doorkeeper/DiffusionDoorkeeperCommitFeedStoryPublisher.php
+++ b/src/applications/diffusion/doorkeeper/DiffusionDoorkeeperCommitFeedStoryPublisher.php
@@ -172,8 +172,7 @@
   }
 
   private function getTitlePrefix(PhabricatorRepositoryCommit $commit) {
-    $prefix_key = 'metamta.diffusion.subject-prefix';
-    return PhabricatorEnv::getEnvConfig($prefix_key);
+    return pht('[Diffusion]');
   }
 
 }
diff --git a/src/applications/files/config/PhabricatorFilesConfigOptions.php b/src/applications/files/config/PhabricatorFilesConfigOptions.php
--- a/src/applications/files/config/PhabricatorFilesConfigOptions.php
+++ b/src/applications/files/config/PhabricatorFilesConfigOptions.php
@@ -197,11 +197,6 @@
             "Set this to a valid Amazon S3 bucket to store files there. You ".
             "must also configure S3 access keys in the 'Amazon Web Services' ".
             "group.")),
-     $this->newOption(
-        'metamta.files.subject-prefix',
-        'string',
-        '[File]')
-        ->setDescription(pht('Subject prefix for Files email.')),
      $this->newOption('files.enable-imagemagick', 'bool', false)
        ->setBoolOptions(
          array(
diff --git a/src/applications/files/editor/PhabricatorFileEditor.php b/src/applications/files/editor/PhabricatorFileEditor.php
--- a/src/applications/files/editor/PhabricatorFileEditor.php
+++ b/src/applications/files/editor/PhabricatorFileEditor.php
@@ -27,7 +27,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.files.subject-prefix');
+    return pht('[File]');
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
diff --git a/src/applications/files/mail/FileCreateMailReceiver.php b/src/applications/files/mail/FileCreateMailReceiver.php
--- a/src/applications/files/mail/FileCreateMailReceiver.php
+++ b/src/applications/files/mail/FileCreateMailReceiver.php
@@ -33,8 +33,7 @@
     } else {
       $subject = pht('You successfully uploaded a file.');
     }
-    $subject_prefix =
-      PhabricatorEnv::getEnvConfig('metamta.files.subject-prefix');
+    $subject_prefix = pht('[File]');
 
     $file_uris = array();
     foreach ($attachment_phids as $phid) {
diff --git a/src/applications/legalpad/config/PhabricatorLegalpadConfigOptions.php b/src/applications/legalpad/config/PhabricatorLegalpadConfigOptions.php
deleted file mode 100644
--- a/src/applications/legalpad/config/PhabricatorLegalpadConfigOptions.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-final class PhabricatorLegalpadConfigOptions
-  extends PhabricatorApplicationConfigOptions {
-
-  public function getName() {
-    return pht('Legalpad');
-  }
-
-  public function getDescription() {
-    return pht('Configure Legalpad.');
-  }
-
-  public function getIcon() {
-    return 'fa-gavel';
-  }
-
-  public function getGroup() {
-    return 'apps';
-  }
-
-  public function getOptions() {
-    return array(
-      $this->newOption(
-        'metamta.legalpad.subject-prefix',
-        'string',
-        '[Legalpad]')
-        ->setDescription(pht('Subject prefix for Legalpad email.')),
-    );
-  }
-
-}
diff --git a/src/applications/legalpad/editor/LegalpadDocumentEditor.php b/src/applications/legalpad/editor/LegalpadDocumentEditor.php
--- a/src/applications/legalpad/editor/LegalpadDocumentEditor.php
+++ b/src/applications/legalpad/editor/LegalpadDocumentEditor.php
@@ -166,7 +166,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.legalpad.subject-prefix');
+    return pht('[Legalpad]');
   }
 
 
diff --git a/src/applications/macro/config/PhabricatorMacroConfigOptions.php b/src/applications/macro/config/PhabricatorMacroConfigOptions.php
deleted file mode 100644
--- a/src/applications/macro/config/PhabricatorMacroConfigOptions.php
+++ /dev/null
@@ -1,29 +0,0 @@
-<?php
-
-final class PhabricatorMacroConfigOptions
-  extends PhabricatorApplicationConfigOptions {
-
-  public function getName() {
-    return pht('Macro');
-  }
-
-  public function getDescription() {
-    return pht('Configure Macro.');
-  }
-
-  public function getIcon() {
-    return 'fa-file-image-o';
-  }
-
-  public function getGroup() {
-    return 'apps';
-  }
-
-  public function getOptions() {
-    return array(
-      $this->newOption('metamta.macro.subject-prefix', 'string', '[Macro]')
-        ->setDescription(pht('Subject prefix for Macro email.')),
-    );
-  }
-
-}
diff --git a/src/applications/macro/editor/PhabricatorMacroEditor.php b/src/applications/macro/editor/PhabricatorMacroEditor.php
--- a/src/applications/macro/editor/PhabricatorMacroEditor.php
+++ b/src/applications/macro/editor/PhabricatorMacroEditor.php
@@ -57,7 +57,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.macro.subject-prefix');
+    return pht('[Macro]');
   }
 
   protected function shouldPublishFeedStory(
diff --git a/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php b/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php
--- a/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php
+++ b/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php
@@ -459,11 +459,6 @@
             '%s configuration option. The default value (`90`) '.
             'corresponds to the default "Needs Triage" priority.',
             'maniphest.priorities')),
-      $this->newOption(
-        'metamta.maniphest.subject-prefix',
-        'string',
-        '[Maniphest]')
-        ->setDescription(pht('Subject prefix for Maniphest mail.')),
       $this->newOption('maniphest.points', $points_type, array())
         ->setSummary(pht('Configure point values for tasks.'))
         ->setDescription($points_description)
diff --git a/src/applications/maniphest/editor/ManiphestTransactionEditor.php b/src/applications/maniphest/editor/ManiphestTransactionEditor.php
--- a/src/applications/maniphest/editor/ManiphestTransactionEditor.php
+++ b/src/applications/maniphest/editor/ManiphestTransactionEditor.php
@@ -155,7 +155,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.maniphest.subject-prefix');
+    return pht('[Maniphest]');
   }
 
   protected function getMailThreadID(PhabricatorLiskDAO $object) {
diff --git a/src/applications/owners/config/PhabricatorOwnersConfigOptions.php b/src/applications/owners/config/PhabricatorOwnersConfigOptions.php
--- a/src/applications/owners/config/PhabricatorOwnersConfigOptions.php
+++ b/src/applications/owners/config/PhabricatorOwnersConfigOptions.php
@@ -36,8 +36,6 @@
     $fields_example = id(new PhutilJSON())->encodeFormatted($fields_example);
 
     return array(
-      $this->newOption('metamta.package.subject-prefix', 'string', '[Package]')
-        ->setDescription(pht('Subject prefix for Owners email.')),
       $this->newOption('owners.fields', $custom_field_type, $default_fields)
         ->setCustomData($field_base_class)
         ->setDescription(pht('Select and reorder package fields.')),
diff --git a/src/applications/owners/editor/PhabricatorOwnersPackageTransactionEditor.php b/src/applications/owners/editor/PhabricatorOwnersPackageTransactionEditor.php
--- a/src/applications/owners/editor/PhabricatorOwnersPackageTransactionEditor.php
+++ b/src/applications/owners/editor/PhabricatorOwnersPackageTransactionEditor.php
@@ -27,7 +27,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.package.subject-prefix');
+    return pht('[Package]');
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
diff --git a/src/applications/paste/config/PhabricatorPasteConfigOptions.php b/src/applications/paste/config/PhabricatorPasteConfigOptions.php
deleted file mode 100644
--- a/src/applications/paste/config/PhabricatorPasteConfigOptions.php
+++ /dev/null
@@ -1,32 +0,0 @@
-<?php
-
-final class PhabricatorPasteConfigOptions
-  extends PhabricatorApplicationConfigOptions {
-
-  public function getName() {
-    return pht('Paste');
-  }
-
-  public function getDescription() {
-    return pht('Configure Paste.');
-  }
-
-  public function getIcon() {
-    return 'fa-paste';
-  }
-
-  public function getGroup() {
-    return 'apps';
-  }
-
-  public function getOptions() {
-    return array(
-      $this->newOption(
-        'metamta.paste.subject-prefix',
-        'string',
-        '[Paste]')
-        ->setDescription(pht('Subject prefix for Paste email.')),
-    );
-  }
-
-}
diff --git a/src/applications/paste/editor/PhabricatorPasteEditor.php b/src/applications/paste/editor/PhabricatorPasteEditor.php
--- a/src/applications/paste/editor/PhabricatorPasteEditor.php
+++ b/src/applications/paste/editor/PhabricatorPasteEditor.php
@@ -41,7 +41,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.paste.subject-prefix');
+    return pht('[Paste]');
   }
 
   protected function getMailTo(PhabricatorLiskDAO $object) {
diff --git a/src/applications/paste/mail/PasteCreateMailReceiver.php b/src/applications/paste/mail/PasteCreateMailReceiver.php
--- a/src/applications/paste/mail/PasteCreateMailReceiver.php
+++ b/src/applications/paste/mail/PasteCreateMailReceiver.php
@@ -44,8 +44,7 @@
       return;
     }
 
-    $subject_prefix =
-      PhabricatorEnv::getEnvConfig('metamta.paste.subject-prefix');
+    $subject_prefix = pht('[Paste]');
     $subject = pht('You successfully created a paste.');
     $paste_uri = PhabricatorEnv::getProductionURI($paste->getURI());
     $body = new PhabricatorMetaMTAMailBody();
diff --git a/src/applications/pholio/config/PhabricatorPholioConfigOptions.php b/src/applications/pholio/config/PhabricatorPholioConfigOptions.php
deleted file mode 100644
--- a/src/applications/pholio/config/PhabricatorPholioConfigOptions.php
+++ /dev/null
@@ -1,29 +0,0 @@
-<?php
-
-final class PhabricatorPholioConfigOptions
-  extends PhabricatorApplicationConfigOptions {
-
-  public function getName() {
-    return pht('Pholio');
-  }
-
-  public function getDescription() {
-    return pht('Configure Pholio.');
-  }
-
-  public function getIcon() {
-    return 'fa-camera-retro';
-  }
-
-  public function getGroup() {
-    return 'apps';
-  }
-
-  public function getOptions() {
-    return array(
-      $this->newOption('metamta.pholio.subject-prefix', 'string', '[Pholio]')
-        ->setDescription(pht('Subject prefix for Pholio email.')),
-    );
-  }
-
-}
diff --git a/src/applications/pholio/editor/PholioMockEditor.php b/src/applications/pholio/editor/PholioMockEditor.php
--- a/src/applications/pholio/editor/PholioMockEditor.php
+++ b/src/applications/pholio/editor/PholioMockEditor.php
@@ -139,7 +139,7 @@
   }
 
   protected function getMailSubjectPrefix() {
-    return PhabricatorEnv::getEnvConfig('metamta.pholio.subject-prefix');
+    return pht('[Pholio]');
   }
 
   public function getMailTagsMap() {
diff --git a/src/applications/phriction/config/PhabricatorPhrictionConfigOptions.php b/src/applications/phriction/config/PhabricatorPhrictionConfigOptions.php
deleted file mode 100644
--- a/src/applications/phriction/config/PhabricatorPhrictionConfigOptions.php
+++ /dev/null
@@ -1,30 +0,0 @@
-<?php
-
-final class PhabricatorPhrictionConfigOptions
-  extends PhabricatorApplicationConfigOptions {
-
-  public function getName() {
-    return pht('Phriction');
-  }
-
-  public function getDescription() {
-    return pht('Options related to Phriction (wiki).');
-  }
-
-  public function getIcon() {
-    return 'fa-book';
-  }
-
-  public function getGroup() {
-    return 'apps';
-  }
-
-  public function getOptions() {
-    return array(
-      $this->newOption(
-        'metamta.phriction.subject-prefix', 'string', '[Phriction]')
-        ->setDescription(pht('Subject prefix for Phriction email.')),
-    );
-  }
-
-}
diff --git a/src/applications/repository/worker/PhabricatorRepositoryPushMailWorker.php b/src/applications/repository/worker/PhabricatorRepositoryPushMailWorker.php
--- a/src/applications/repository/worker/PhabricatorRepositoryPushMailWorker.php
+++ b/src/applications/repository/worker/PhabricatorRepositoryPushMailWorker.php
@@ -99,7 +99,7 @@
       $body->addTextSection(pht('REFERENCES'), implode("\n", $ref_lines));
     }
 
-    $prefix = PhabricatorEnv::getEnvConfig('metamta.diffusion.subject-prefix');
+    $prefix = pht('[Diffusion]');
 
     $parts = array();
     if ($commit_count) {