diff --git a/src/applications/audit/editor/PhabricatorAuditCommentEditor.php b/src/applications/audit/editor/PhabricatorAuditCommentEditor.php
index 5567af5774..f5aeb49c17 100644
--- a/src/applications/audit/editor/PhabricatorAuditCommentEditor.php
+++ b/src/applications/audit/editor/PhabricatorAuditCommentEditor.php
@@ -39,8 +39,7 @@ final class PhabricatorAuditCommentEditor extends PhabricatorEditor {
   }
 
   public static function newReplyHandlerForCommit($commit) {
-    $reply_handler = PhabricatorEnv::newObjectFromConfig(
-      'metamta.diffusion.reply-handler');
+    $reply_handler = new PhabricatorAuditReplyHandler();
     $reply_handler->setMailReceiver($commit);
     return $reply_handler;
   }
diff --git a/src/applications/audit/editor/PhabricatorAuditEditor.php b/src/applications/audit/editor/PhabricatorAuditEditor.php
index d98f866afa..4ce57bd95c 100644
--- a/src/applications/audit/editor/PhabricatorAuditEditor.php
+++ b/src/applications/audit/editor/PhabricatorAuditEditor.php
@@ -588,10 +588,8 @@ final class PhabricatorAuditEditor
     return $result;
   }
 
-
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
-    $reply_handler = PhabricatorEnv::newObjectFromConfig(
-      'metamta.diffusion.reply-handler');
+    $reply_handler = new PhabricatorAuditReplyHandler();
     $reply_handler->setMailReceiver($object);
     return $reply_handler;
   }
diff --git a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
index df60dab08d..c7fde5f6e4 100644
--- a/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
+++ b/src/applications/config/check/PhabricatorExtraConfigSetupCheck.php
@@ -164,6 +164,9 @@ final class PhabricatorExtraConfigSetupCheck extends PhabricatorSetupCheck {
       'Configure a reply domain with "%s".',
       'metamta.reply-handler-domain');
 
+    $reply_handler_reason = pht(
+      'Reply handlers can no longer be overridden with configuration.');
+
     $ancient_config += array(
       'phid.external-loaders' =>
         pht(
@@ -233,6 +236,11 @@ final class PhabricatorExtraConfigSetupCheck extends PhabricatorSetupCheck {
       'metamta.macro.reply-handler-domain' => $reply_domain_reason,
       'metamta.maniphest.reply-handler-domain' => $reply_domain_reason,
       'metamta.pholio.reply-handler-domain' => $reply_domain_reason,
+
+      'metamta.diffusion.reply-handler' => $reply_handler_reason,
+      'metamta.differential.reply-handler' => $reply_handler_reason,
+      'metamta.maniphest.reply-handler' => $reply_handler_reason,
+      'metamta.package.reply-handler' => $reply_handler_reason,
     );
 
     return $ancient_config;
diff --git a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
index 08492aa644..6169d0df88 100644
--- a/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
+++ b/src/applications/differential/config/PhabricatorDifferentialConfigOptions.php
@@ -244,13 +244,6 @@ final class PhabricatorDifferentialConfigOptions
           pht(
             "Similar to `differential.days-fresh` but marks stale revisions. ".
             "If the revision is even older than it is when marked as 'old'.")),
-      $this->newOption(
-        'metamta.differential.reply-handler',
-        'class',
-        'DifferentialReplyHandler')
-        ->setLocked(true)
-        ->setBaseClass('PhabricatorMailReplyHandler')
-        ->setDescription(pht('Alternate reply handler class.')),
       $this->newOption(
         'metamta.differential.subject-prefix',
         'string',
diff --git a/src/applications/differential/mail/DifferentialMail.php b/src/applications/differential/mail/DifferentialMail.php
index e285ee37c7..07494c5282 100644
--- a/src/applications/differential/mail/DifferentialMail.php
+++ b/src/applications/differential/mail/DifferentialMail.php
@@ -4,11 +4,8 @@ abstract class DifferentialMail extends PhabricatorMail {
 
   public static function newReplyHandlerForRevision(
     DifferentialRevision $revision) {
-
-    $reply_handler = PhabricatorEnv::newObjectFromConfig(
-      'metamta.differential.reply-handler');
+    $reply_handler = new DifferentialReplyHandler();
     $reply_handler->setMailReceiver($revision);
-
     return $reply_handler;
   }
 
diff --git a/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php b/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php
index f6dfb92762..3455077100 100644
--- a/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php
+++ b/src/applications/diffusion/config/PhabricatorDiffusionConfigOptions.php
@@ -26,13 +26,6 @@ final class PhabricatorDiffusionConfigOptions
         'string',
         '[Diffusion]')
         ->setDescription(pht('Subject prefix for Diffusion mail.')),
-      $this->newOption(
-        'metamta.diffusion.reply-handler',
-        'class',
-        'PhabricatorAuditReplyHandler')
-        ->setLocked(true)
-        ->setBaseClass('PhabricatorMailReplyHandler')
-        ->setDescription(pht('Override mail reply handler class.')),
       $this->newOption(
         'metamta.diffusion.attach-patches',
         'bool',
diff --git a/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php b/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php
index cef998fb66..9f7245e515 100644
--- a/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php
+++ b/src/applications/maniphest/config/PhabricatorManiphestConfigOptions.php
@@ -272,13 +272,6 @@ EOTEXT
             'review and adjust available priorities by using the '.
             '{{maniphest.priorities}} configuration option. The default value '.
             '(`90`) corresponds to the default "Needs Triage" priority.')),
-      $this->newOption(
-        'metamta.maniphest.reply-handler',
-        'class',
-        'ManiphestReplyHandler')
-        ->setLocked(true)
-        ->setBaseClass('PhabricatorMailReplyHandler')
-        ->setDescription(pht('Override reply handler class.')),
       $this->newOption(
         'metamta.maniphest.subject-prefix',
         'string',
diff --git a/src/applications/maniphest/mail/ManiphestCreateMailReceiver.php b/src/applications/maniphest/mail/ManiphestCreateMailReceiver.php
index d28beb3b74..2df618c879 100644
--- a/src/applications/maniphest/mail/ManiphestCreateMailReceiver.php
+++ b/src/applications/maniphest/mail/ManiphestCreateMailReceiver.php
@@ -19,8 +19,7 @@ final class ManiphestCreateMailReceiver extends PhabricatorMailReceiver {
     $task = ManiphestTask::initializeNewTask($sender);
     $task->setOriginalEmailSource($mail->getHeader('From'));
 
-    $handler = PhabricatorEnv::newObjectFromConfig(
-      'metamta.maniphest.reply-handler');
+    $handler = new ManiphestReplyHandler();
     $handler->setMailReceiver($task);
 
     $handler->setActor($sender);
diff --git a/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php b/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php
index 59d97cfcc8..672152c2ff 100644
--- a/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php
+++ b/src/applications/maniphest/mail/ManiphestTaskMailReceiver.php
@@ -29,8 +29,7 @@ final class ManiphestTaskMailReceiver extends PhabricatorObjectMailReceiver {
     PhabricatorLiskDAO $object,
     PhabricatorUser $sender) {
 
-    $handler = PhabricatorEnv::newObjectFromConfig(
-      'metamta.maniphest.reply-handler');
+    $handler = new ManiphestReplyHandler();
     $handler->setMailReceiver($object);
 
     $handler->setActor($sender);
diff --git a/src/applications/owners/config/PhabricatorOwnersConfigOptions.php b/src/applications/owners/config/PhabricatorOwnersConfigOptions.php
index ec0944b818..7d7b3e958d 100644
--- a/src/applications/owners/config/PhabricatorOwnersConfigOptions.php
+++ b/src/applications/owners/config/PhabricatorOwnersConfigOptions.php
@@ -21,13 +21,6 @@ final class PhabricatorOwnersConfigOptions
 
   public function getOptions() {
     return array(
-      $this->newOption(
-        'metamta.package.reply-handler',
-        'class',
-        'OwnersPackageReplyHandler')
-        ->setLocked(true)
-        ->setBaseClass('PhabricatorMailReplyHandler')
-        ->setDescription(pht('Reply handler for owners mail.')),
       $this->newOption('metamta.package.subject-prefix', 'string', '[Package]')
         ->setDescription(pht('Subject prefix for Owners email.')),
     );
diff --git a/src/applications/owners/mail/PackageMail.php b/src/applications/owners/mail/PackageMail.php
index 58060d9633..00a8b196f6 100644
--- a/src/applications/owners/mail/PackageMail.php
+++ b/src/applications/owners/mail/PackageMail.php
@@ -201,8 +201,7 @@ abstract class PackageMail extends PhabricatorMail {
   }
 
   private function newReplyHandler() {
-    $reply_handler = PhabricatorEnv::newObjectFromConfig(
-      'metamta.package.reply-handler');
+    $reply_handler = new OwnersPackageReplyHandler();
     $reply_handler->setMailReceiver($this->getPackage());
     return $reply_handler;
   }