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
@@ -2146,6 +2146,7 @@
     'PhabricatorSettingsPanelDiffPreferences' => 'applications/settings/panel/PhabricatorSettingsPanelDiffPreferences.php',
     'PhabricatorSettingsPanelDisplayPreferences' => 'applications/settings/panel/PhabricatorSettingsPanelDisplayPreferences.php',
     'PhabricatorSettingsPanelEmailAddresses' => 'applications/settings/panel/PhabricatorSettingsPanelEmailAddresses.php',
+    'PhabricatorSettingsPanelEmailFormat' => 'applications/settings/panel/PhabricatorSettingsPanelEmailFormat.php',
     'PhabricatorSettingsPanelEmailPreferences' => 'applications/settings/panel/PhabricatorSettingsPanelEmailPreferences.php',
     'PhabricatorSettingsPanelExternalAccounts' => 'applications/settings/panel/PhabricatorSettingsPanelExternalAccounts.php',
     'PhabricatorSettingsPanelHomePreferences' => 'applications/settings/panel/PhabricatorSettingsPanelHomePreferences.php',
@@ -5018,6 +5019,7 @@
     'PhabricatorSettingsPanelDiffPreferences' => 'PhabricatorSettingsPanel',
     'PhabricatorSettingsPanelDisplayPreferences' => 'PhabricatorSettingsPanel',
     'PhabricatorSettingsPanelEmailAddresses' => 'PhabricatorSettingsPanel',
+    'PhabricatorSettingsPanelEmailFormat' => 'PhabricatorSettingsPanel',
     'PhabricatorSettingsPanelEmailPreferences' => 'PhabricatorSettingsPanel',
     'PhabricatorSettingsPanelExternalAccounts' => 'PhabricatorSettingsPanel',
     'PhabricatorSettingsPanelHomePreferences' => 'PhabricatorSettingsPanel',
diff --git a/src/applications/settings/panel/PhabricatorSettingsPanelEmailFormat.php b/src/applications/settings/panel/PhabricatorSettingsPanelEmailFormat.php
new file mode 100644
--- /dev/null
+++ b/src/applications/settings/panel/PhabricatorSettingsPanelEmailFormat.php
@@ -0,0 +1,182 @@
+<?php
+
+final class PhabricatorSettingsPanelEmailFormat
+  extends PhabricatorSettingsPanel {
+
+  public function getPanelKey() {
+    return 'emailformat';
+  }
+
+  public function getPanelName() {
+    return pht('Email Format');
+  }
+
+  public function getPanelGroup() {
+    return pht('Email');
+  }
+
+  public function processRequest(AphrontRequest $request) {
+    $user = $request->getUser();
+
+    $preferences = $user->loadPreferences();
+
+    $pref_re_prefix = PhabricatorUserPreferences::PREFERENCE_RE_PREFIX;
+    $pref_vary = PhabricatorUserPreferences::PREFERENCE_VARY_SUBJECT;
+
+    $errors = array();
+    if ($request->isFormPost()) {
+
+      if (PhabricatorMetaMTAMail::shouldMultiplexAllMail()) {
+        if ($request->getStr($pref_re_prefix) == 'default') {
+          $preferences->unsetPreference($pref_re_prefix);
+        } else {
+          $preferences->setPreference(
+            $pref_re_prefix,
+            $request->getBool($pref_re_prefix));
+        }
+
+        if ($request->getStr($pref_vary) == 'default') {
+          $preferences->unsetPreference($pref_vary);
+        } else {
+          $preferences->setPreference(
+            $pref_vary,
+            $request->getBool($pref_vary));
+        }
+      }
+
+      $preferences->save();
+
+      return id(new AphrontRedirectResponse())
+        ->setURI($this->getPanelURI('?saved=true'));
+    }
+
+    $re_prefix_default = PhabricatorEnv::getEnvConfig('metamta.re-prefix')
+      ? pht('Enabled')
+      : pht('Disabled');
+
+    $vary_default = PhabricatorEnv::getEnvConfig('metamta.vary-subjects')
+      ? pht('Vary')
+      : pht('Do Not Vary');
+
+    $re_prefix_value = $preferences->getPreference($pref_re_prefix);
+    if ($re_prefix_value === null) {
+      $re_prefix_value = 'default';
+    } else {
+      $re_prefix_value = $re_prefix_value
+        ? 'true'
+        : 'false';
+    }
+
+    $vary_value = $preferences->getPreference($pref_vary);
+    if ($vary_value === null) {
+      $vary_value = 'default';
+    } else {
+      $vary_value = $vary_value
+        ? 'true'
+        : 'false';
+    }
+
+    $form = new AphrontFormView();
+    $form
+      ->setUser($user);
+
+    if (PhabricatorMetaMTAMail::shouldMultiplexAllMail()) {
+      $re_control = id(new AphrontFormSelectControl())
+        ->setName($pref_re_prefix)
+        ->setOptions(
+          array(
+            'default'   => pht('Use Server Default (%s)', $re_prefix_default),
+            'true'      => pht('Enable "Re:" prefix'),
+            'false'     => pht('Disable "Re:" prefix'),
+          ))
+        ->setValue($re_prefix_value);
+
+      $vary_control = id(new AphrontFormSelectControl())
+        ->setName($pref_vary)
+        ->setOptions(
+          array(
+            'default'   => pht('Use Server Default (%s)', $vary_default),
+            'true'      => pht('Vary Subjects'),
+            'false'     => pht('Do Not Vary Subjects'),
+          ))
+        ->setValue($vary_value);
+    } else {
+      $re_control = id(new AphrontFormStaticControl())
+        ->setValue('Server Default ('.$re_prefix_default.')');
+
+      $vary_control = id(new AphrontFormStaticControl())
+        ->setValue('Server Default ('.$vary_default.')');
+    }
+
+    $form
+      ->appendRemarkupInstructions(
+        pht(
+          'These settings fine-tune some technical aspects of how email is '.
+          'formatted. You may be able to adjust them to make mail more '.
+          'useful or improve threading.'));
+
+    if (!PhabricatorMetaMTAMail::shouldMultiplexAllMail()) {
+      $form->appendRemarkupInstructions(
+        pht(
+          'NOTE: This install of Phabricator is configured to send a '.
+          'single mail message to all recipients, so all settings are '.
+          'locked at the server default value.'));
+    }
+
+    $form
+      ->appendRemarkupInstructions('')
+      ->appendRemarkupInstructions(
+        pht(
+          'The **Add "Re:" Prefix** setting adds "Re:" in front of all '.
+          'messages, even if they are not replies. If you use **Mail.app** on '.
+          'Mac OS X, this may improve mail threading.'.
+          "\n\n".
+          "| Setting                | Example Mail Subject\n".
+          "|------------------------|----------------\n".
+          "| Enable \"Re:\" Prefix  | ".
+          "`Re: [Differential] [Accepted] D123: Example Revision`\n".
+          "| Disable \"Re:\" Prefix | ".
+          "`[Differential] [Accepted] D123: Example Revision`"))
+      ->appendChild(
+        $re_control
+          ->setLabel(pht('Add "Re:" Prefix')))
+      ->appendRemarkupInstructions('')
+      ->appendRemarkupInstructions(
+        pht(
+          'With **Vary Subjects** enabled, most mail subject lines will '.
+          'include a brief description of their content, like **[Closed]** '.
+          'for a notification about someone closing a task.'.
+          "\n\n".
+          "| Setting              | Example Mail Subject\n".
+          "|----------------------|----------------\n".
+          "| Vary Subjects        | ".
+          "`[Maniphest] [Closed] T123: Example Task`\n".
+          "| Do Not Vary Subjects | ".
+          "`[Maniphest] T123: Example Task`\n".
+          "\n".
+          'This can make mail more useful, but some clients have difficulty '.
+          'threading these messages. Disabling this option may improve '.
+          'threading, at the cost of less useful subject lines.'))
+      ->appendChild(
+        $vary_control
+          ->setLabel(pht('Vary Subjects')));
+
+    $form
+      ->appendChild(
+        id(new AphrontFormSubmitControl())
+          ->setValue(pht('Save Preferences')));
+
+    $form_box = id(new PHUIObjectBoxView())
+      ->setHeaderText(pht('Email Format'))
+      ->setFormSaved($request->getStr('saved'))
+      ->setFormErrors($errors)
+      ->setForm($form);
+
+    return id(new AphrontNullView())
+      ->appendChild(
+        array(
+          $form_box,
+        ));
+  }
+
+}
diff --git a/src/applications/settings/panel/PhabricatorSettingsPanelEmailPreferences.php b/src/applications/settings/panel/PhabricatorSettingsPanelEmailPreferences.php
--- a/src/applications/settings/panel/PhabricatorSettingsPanelEmailPreferences.php
+++ b/src/applications/settings/panel/PhabricatorSettingsPanelEmailPreferences.php
@@ -20,31 +20,10 @@
 
     $preferences = $user->loadPreferences();
 
-    $pref_re_prefix = PhabricatorUserPreferences::PREFERENCE_RE_PREFIX;
-    $pref_vary = PhabricatorUserPreferences::PREFERENCE_VARY_SUBJECT;
     $pref_no_self_mail = PhabricatorUserPreferences::PREFERENCE_NO_SELF_MAIL;
 
     $errors = array();
     if ($request->isFormPost()) {
-
-      if (PhabricatorMetaMTAMail::shouldMultiplexAllMail()) {
-        if ($request->getStr($pref_re_prefix) == 'default') {
-          $preferences->unsetPreference($pref_re_prefix);
-        } else {
-          $preferences->setPreference(
-            $pref_re_prefix,
-            $request->getBool($pref_re_prefix));
-        }
-
-        if ($request->getStr($pref_vary) == 'default') {
-          $preferences->unsetPreference($pref_vary);
-        } else {
-          $preferences->setPreference(
-            $pref_vary,
-            $request->getBool($pref_vary));
-        }
-      }
-
       $preferences->setPreference(
         $pref_no_self_mail,
         $request->getStr($pref_no_self_mail));
@@ -74,32 +53,6 @@
         ->setURI($this->getPanelURI('?saved=true'));
     }
 
-    $re_prefix_default = PhabricatorEnv::getEnvConfig('metamta.re-prefix')
-      ? pht('Enabled')
-      : pht('Disabled');
-
-    $vary_default = PhabricatorEnv::getEnvConfig('metamta.vary-subjects')
-      ? pht('Vary')
-      : pht('Do Not Vary');
-
-    $re_prefix_value = $preferences->getPreference($pref_re_prefix);
-    if ($re_prefix_value === null) {
-      $re_prefix_value = 'default';
-    } else {
-      $re_prefix_value = $re_prefix_value
-        ? 'true'
-        : 'false';
-    }
-
-    $vary_value = $preferences->getPreference($pref_vary);
-    if ($vary_value === null) {
-      $vary_value = 'default';
-    } else {
-      $vary_value = $vary_value
-        ? 'true'
-        : 'false';
-    }
-
     $form = new AphrontFormView();
     $form
       ->setUser($user)
@@ -115,48 +68,6 @@
           ->setCaption(pht('You can disable email about your own actions.'))
           ->setValue($preferences->getPreference($pref_no_self_mail, 0)));
 
-    if (PhabricatorMetaMTAMail::shouldMultiplexAllMail()) {
-      $re_control = id(new AphrontFormSelectControl())
-        ->setName($pref_re_prefix)
-        ->setOptions(
-          array(
-            'default'   => pht('Use Server Default (%s)', $re_prefix_default),
-            'true'      => pht('Enable "Re:" prefix'),
-            'false'     => pht('Disable "Re:" prefix'),
-          ))
-        ->setValue($re_prefix_value);
-
-      $vary_control = id(new AphrontFormSelectControl())
-        ->setName($pref_vary)
-        ->setOptions(
-          array(
-            'default'   => pht('Use Server Default (%s)', $vary_default),
-            'true'      => pht('Vary Subjects'),
-            'false'     => pht('Do Not Vary Subjects'),
-          ))
-        ->setValue($vary_value);
-    } else {
-      $re_control = id(new AphrontFormStaticControl())
-        ->setValue('Server Default ('.$re_prefix_default.')');
-
-      $vary_control = id(new AphrontFormStaticControl())
-        ->setValue('Server Default ('.$vary_default.')');
-    }
-
-    $form
-      ->appendChild(
-        $re_control
-          ->setLabel(pht('Add "Re:" Prefix'))
-          ->setCaption(
-            pht('Enable this option to fix threading in Mail.app on OS X Lion,'.
-            ' or if you like "Re:" in your email subjects.')))
-      ->appendChild(
-        $vary_control
-          ->setLabel(pht('Vary Subjects'))
-          ->setCaption(
-            pht('This option adds more information to email subjects, but may '.
-            'break threading in some clients.')));
-
     $mailtags = $preferences->getPreference('mailtags', array());
 
     $form->appendChild(