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
@@ -2020,15 +2020,6 @@
     'PhabricatorMailReplyHandler' => 'applications/metamta/replyhandler/PhabricatorMailReplyHandler.php',
     'PhabricatorMailSetupCheck' => 'applications/config/check/PhabricatorMailSetupCheck.php',
     'PhabricatorMailgunConfigOptions' => 'applications/config/option/PhabricatorMailgunConfigOptions.php',
-    'PhabricatorMailingListDatasource' => 'applications/mailinglists/typeahead/PhabricatorMailingListDatasource.php',
-    'PhabricatorMailingListListPHIDType' => 'applications/mailinglists/phid/PhabricatorMailingListListPHIDType.php',
-    'PhabricatorMailingListQuery' => 'applications/mailinglists/query/PhabricatorMailingListQuery.php',
-    'PhabricatorMailingListSearchEngine' => 'applications/mailinglists/query/PhabricatorMailingListSearchEngine.php',
-    'PhabricatorMailingListsApplication' => 'applications/mailinglists/application/PhabricatorMailingListsApplication.php',
-    'PhabricatorMailingListsController' => 'applications/mailinglists/controller/PhabricatorMailingListsController.php',
-    'PhabricatorMailingListsEditController' => 'applications/mailinglists/controller/PhabricatorMailingListsEditController.php',
-    'PhabricatorMailingListsListController' => 'applications/mailinglists/controller/PhabricatorMailingListsListController.php',
-    'PhabricatorMailingListsManageCapability' => 'applications/mailinglists/capability/PhabricatorMailingListsManageCapability.php',
     'PhabricatorMainMenuSearchView' => 'view/page/menu/PhabricatorMainMenuSearchView.php',
     'PhabricatorMainMenuView' => 'view/page/menu/PhabricatorMainMenuView.php',
     'PhabricatorManagementWorkflow' => 'infrastructure/management/PhabricatorManagementWorkflow.php',
@@ -2067,7 +2058,6 @@
     'PhabricatorMetaMTAMailableDatasource' => 'applications/metamta/typeahead/PhabricatorMetaMTAMailableDatasource.php',
     'PhabricatorMetaMTAMailableFunctionDatasource' => 'applications/metamta/typeahead/PhabricatorMetaMTAMailableFunctionDatasource.php',
     'PhabricatorMetaMTAMailgunReceiveController' => 'applications/metamta/controller/PhabricatorMetaMTAMailgunReceiveController.php',
-    'PhabricatorMetaMTAMailingList' => 'applications/mailinglists/storage/PhabricatorMetaMTAMailingList.php',
     'PhabricatorMetaMTAMemberQuery' => 'applications/metamta/query/PhabricatorMetaMTAMemberQuery.php',
     'PhabricatorMetaMTAPermanentFailureException' => 'applications/metamta/exception/PhabricatorMetaMTAPermanentFailureException.php',
     'PhabricatorMetaMTAReceivedMail' => 'applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php',
@@ -5435,15 +5425,6 @@
     'PhabricatorMailReceiverTestCase' => 'PhabricatorTestCase',
     'PhabricatorMailSetupCheck' => 'PhabricatorSetupCheck',
     'PhabricatorMailgunConfigOptions' => 'PhabricatorApplicationConfigOptions',
-    'PhabricatorMailingListDatasource' => 'PhabricatorTypeaheadDatasource',
-    'PhabricatorMailingListListPHIDType' => 'PhabricatorPHIDType',
-    'PhabricatorMailingListQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
-    'PhabricatorMailingListSearchEngine' => 'PhabricatorApplicationSearchEngine',
-    'PhabricatorMailingListsApplication' => 'PhabricatorApplication',
-    'PhabricatorMailingListsController' => 'PhabricatorController',
-    'PhabricatorMailingListsEditController' => 'PhabricatorMailingListsController',
-    'PhabricatorMailingListsListController' => 'PhabricatorMailingListsController',
-    'PhabricatorMailingListsManageCapability' => 'PhabricatorPolicyCapability',
     'PhabricatorMainMenuSearchView' => 'AphrontView',
     'PhabricatorMainMenuView' => 'AphrontView',
     'PhabricatorManagementWorkflow' => 'PhutilArgumentWorkflow',
@@ -5477,11 +5458,6 @@
     'PhabricatorMetaMTAMailableDatasource' => 'PhabricatorTypeaheadCompositeDatasource',
     'PhabricatorMetaMTAMailableFunctionDatasource' => 'PhabricatorTypeaheadCompositeDatasource',
     'PhabricatorMetaMTAMailgunReceiveController' => 'PhabricatorMetaMTAController',
-    'PhabricatorMetaMTAMailingList' => array(
-      'PhabricatorMetaMTADAO',
-      'PhabricatorPolicyInterface',
-      'PhabricatorDestructibleInterface',
-    ),
     'PhabricatorMetaMTAMemberQuery' => 'PhabricatorQuery',
     'PhabricatorMetaMTAPermanentFailureException' => 'Exception',
     'PhabricatorMetaMTAReceivedMail' => 'PhabricatorMetaMTADAO',
diff --git a/src/applications/differential/customfield/DifferentialSubscribersField.php b/src/applications/differential/customfield/DifferentialSubscribersField.php
--- a/src/applications/differential/customfield/DifferentialSubscribersField.php
+++ b/src/applications/differential/customfield/DifferentialSubscribersField.php
@@ -78,7 +78,6 @@
       array(
         PhabricatorPeopleUserPHIDType::TYPECONST,
         PhabricatorProjectProjectPHIDType::TYPECONST,
-        PhabricatorMailingListListPHIDType::TYPECONST,
       ));
   }
 
diff --git a/src/applications/mailinglists/application/PhabricatorMailingListsApplication.php b/src/applications/mailinglists/application/PhabricatorMailingListsApplication.php
deleted file mode 100644
--- a/src/applications/mailinglists/application/PhabricatorMailingListsApplication.php
+++ /dev/null
@@ -1,48 +0,0 @@
-<?php
-
-final class PhabricatorMailingListsApplication extends PhabricatorApplication {
-
-  public function getName() {
-    return pht('Mailing Lists');
-  }
-
-  public function getBaseURI() {
-    return '/mailinglists/';
-  }
-
-  public function getShortDescription() {
-    return pht('Manage External Lists');
-  }
-
-  public function getFontIcon() {
-    return 'fa-mail-reply-all';
-  }
-
-  public function getApplicationGroup() {
-    return self::GROUP_ADMIN;
-  }
-
-  public function getRoutes() {
-    return array(
-      '/mailinglists/' => array(
-        '(?:query/(?P<queryKey>[^/]+)/)?'
-          => 'PhabricatorMailingListsListController',
-        'edit/(?:(?P<id>[1-9]\d*)/)?'
-          => 'PhabricatorMailingListsEditController',
-      ),
-    );
-  }
-
-  public function getTitleGlyph() {
-    return '@';
-  }
-
-  protected function getCustomCapabilities() {
-    return array(
-      PhabricatorMailingListsManageCapability::CAPABILITY => array(
-        'default' => PhabricatorPolicies::POLICY_ADMIN,
-      ),
-    );
-  }
-
-}
diff --git a/src/applications/mailinglists/capability/PhabricatorMailingListsManageCapability.php b/src/applications/mailinglists/capability/PhabricatorMailingListsManageCapability.php
deleted file mode 100644
--- a/src/applications/mailinglists/capability/PhabricatorMailingListsManageCapability.php
+++ /dev/null
@@ -1,16 +0,0 @@
-<?php
-
-final class PhabricatorMailingListsManageCapability
-  extends PhabricatorPolicyCapability {
-
-  const CAPABILITY = 'mailinglists.manage';
-
-  public function getCapabilityName() {
-    return pht('Can Manage Lists');
-  }
-
-  public function describeCapabilityRejection() {
-    return pht('You do not have permission to manage mailing lists.');
-  }
-
-}
diff --git a/src/applications/mailinglists/controller/PhabricatorMailingListsController.php b/src/applications/mailinglists/controller/PhabricatorMailingListsController.php
deleted file mode 100644
--- a/src/applications/mailinglists/controller/PhabricatorMailingListsController.php
+++ /dev/null
@@ -1,45 +0,0 @@
-<?php
-
-abstract class PhabricatorMailingListsController extends PhabricatorController {
-
-  public function buildSideNavView($for_app = false) {
-    $user = $this->getRequest()->getUser();
-
-    $nav = new AphrontSideNavFilterView();
-    $nav->setBaseURI(new PhutilURI($this->getApplicationURI()));
-
-    if ($for_app) {
-      $nav->addFilter('edit', pht('Create List'));
-    }
-
-    id(new PhabricatorMailingListSearchEngine())
-      ->setViewer($user)
-      ->addNavigationItems($nav->getMenu());
-
-    $nav->selectFilter(null);
-
-    return $nav;
-  }
-
-  public function buildApplicationMenu() {
-    return $this->buildSideNavView(true)->getMenu();
-  }
-
-  protected function buildApplicationCrumbs() {
-    $crumbs = parent::buildApplicationCrumbs();
-
-    $can_manage = $this->hasApplicationCapability(
-      PhabricatorMailingListsManageCapability::CAPABILITY);
-
-    $crumbs->addAction(
-      id(new PHUIListItemView())
-        ->setName(pht('Create List'))
-        ->setHref($this->getApplicationURI('edit/'))
-        ->setIcon('fa-plus-square')
-        ->setDisabled(!$can_manage)
-        ->setWorkflow(!$can_manage));
-
-    return $crumbs;
-  }
-
-}
diff --git a/src/applications/mailinglists/controller/PhabricatorMailingListsEditController.php b/src/applications/mailinglists/controller/PhabricatorMailingListsEditController.php
deleted file mode 100644
--- a/src/applications/mailinglists/controller/PhabricatorMailingListsEditController.php
+++ /dev/null
@@ -1,131 +0,0 @@
-<?php
-
-final class PhabricatorMailingListsEditController
-  extends PhabricatorMailingListsController {
-
-  public function handleRequest(AphrontRequest $request) {
-    $request = $this->getRequest();
-    $viewer = $request->getUser();
-
-    $this->requireApplicationCapability(
-      PhabricatorMailingListsManageCapability::CAPABILITY);
-
-    $list_id = $request->getURIData('id');
-    if ($list_id) {
-      $page_title = pht('Edit Mailing List');
-      $list = id(new PhabricatorMailingListQuery())
-        ->setViewer($viewer)
-        ->withIDs(array($list_id))
-        ->executeOne();
-      if (!$list) {
-        return new Aphront404Response();
-      }
-    } else {
-      $page_title = pht('Create Mailing List');
-      $list = new PhabricatorMetaMTAMailingList();
-    }
-
-    $e_email = true;
-    $e_uri = null;
-    $e_name = true;
-    $errors = array();
-
-    $crumbs = $this->buildApplicationCrumbs();
-
-    if ($request->isFormPost()) {
-      $list->setName($request->getStr('name'));
-      $list->setEmail($request->getStr('email'));
-      $list->setURI($request->getStr('uri'));
-
-      $e_email = null;
-      $e_name = null;
-
-      if (!strlen($list->getEmail())) {
-        $e_email = pht('Required');
-        $errors[] = pht('Email is required.');
-      }
-
-      if (!strlen($list->getName())) {
-        $e_name = pht('Required');
-        $errors[] = pht('Name is required.');
-      } else if (preg_match('/[ ,]/', $list->getName())) {
-        $e_name = pht('Invalid');
-        $errors[] = pht('Name must not contain spaces or commas.');
-      }
-
-      if ($list->getURI()) {
-        if (!PhabricatorEnv::isValidRemoteURIForLink($list->getURI())) {
-          $e_uri = pht('Invalid');
-          $errors[] = pht('Mailing list URI must point to a valid web page.');
-        }
-      }
-
-      if (!$errors) {
-        try {
-          $list->save();
-          return id(new AphrontRedirectResponse())
-            ->setURI($this->getApplicationURI());
-        } catch (AphrontDuplicateKeyQueryException $ex) {
-          $e_email = pht('Duplicate');
-          $errors[] = pht('Another mailing list already uses that address.');
-        }
-      }
-    }
-
-    $form = new AphrontFormView();
-    $form->setUser($request->getUser());
-    if ($list->getID()) {
-      $form->setAction($this->getApplicationURI('/edit/'.$list->getID().'/'));
-    } else {
-      $form->setAction($this->getApplicationURI('/edit/'));
-    }
-
-    $form
-      ->appendChild(
-        id(new AphrontFormTextControl())
-          ->setLabel(pht('Email'))
-          ->setName('email')
-          ->setValue($list->getEmail())
-          ->setCaption(pht('Email will be delivered to this address.'))
-          ->setError($e_email))
-      ->appendChild(
-        id(new AphrontFormTextControl())
-          ->setLabel(pht('Name'))
-          ->setName('name')
-          ->setError($e_name)
-          ->setCaption(pht('Human-readable display and autocomplete name.'))
-          ->setValue($list->getName()))
-      ->appendChild(
-        id(new AphrontFormTextControl())
-          ->setLabel(pht('URI'))
-          ->setName('uri')
-          ->setError($e_uri)
-          ->setCaption(pht('Optional link to mailing list archives or info.'))
-          ->setValue($list->getURI()))
-      ->appendChild(
-        id(new AphrontFormSubmitControl())
-          ->setValue(pht('Save'))
-          ->addCancelButton($this->getApplicationURI()));
-
-    if ($list->getID()) {
-      $crumbs->addTextCrumb(pht('Edit Mailing List'));
-    } else {
-      $crumbs->addTextCrumb(pht('Create Mailing List'));
-    }
-
-    $form_box = id(new PHUIObjectBoxView())
-      ->setHeaderText($page_title)
-      ->setFormErrors($errors)
-      ->setForm($form);
-
-    return $this->buildApplicationPage(
-      array(
-        $crumbs,
-        $form_box,
-      ),
-      array(
-        'title' => $page_title,
-      ));
-  }
-
-}
diff --git a/src/applications/mailinglists/controller/PhabricatorMailingListsListController.php b/src/applications/mailinglists/controller/PhabricatorMailingListsListController.php
deleted file mode 100644
--- a/src/applications/mailinglists/controller/PhabricatorMailingListsListController.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-
-final class PhabricatorMailingListsListController
-  extends PhabricatorMailingListsController {
-
-  private $queryKey;
-
-  public function shouldAllowPublic() {
-    return true;
-  }
-
-  public function willProcessRequest(array $data) {
-    $this->queryKey = idx($data, 'queryKey');
-  }
-
-  public function processRequest() {
-    $controller = id(new PhabricatorApplicationSearchController())
-      ->setQueryKey($this->queryKey)
-      ->setSearchEngine(new PhabricatorMailingListSearchEngine())
-      ->setNavigation($this->buildSideNavView());
-
-    return $this->delegateToController($controller);
-  }
-
-}
diff --git a/src/applications/mailinglists/phid/PhabricatorMailingListListPHIDType.php b/src/applications/mailinglists/phid/PhabricatorMailingListListPHIDType.php
deleted file mode 100644
--- a/src/applications/mailinglists/phid/PhabricatorMailingListListPHIDType.php
+++ /dev/null
@@ -1,71 +0,0 @@
-<?php
-
-final class PhabricatorMailingListListPHIDType extends PhabricatorPHIDType {
-
-  const TYPECONST = 'MLST';
-
-  public function getTypeName() {
-    return pht('Mailing List');
-  }
-
-  public function getTypeIcon() {
-    return 'fa-envelope-o';
-  }
-
-  public function newObject() {
-    return new PhabricatorMetaMTAMailingList();
-  }
-
-  protected function buildQueryForObjects(
-    PhabricatorObjectQuery $query,
-    array $phids) {
-
-    return id(new PhabricatorMailingListQuery())
-      ->withPHIDs($phids);
-  }
-
-  public function loadHandles(
-    PhabricatorHandleQuery $query,
-    array $handles,
-    array $objects) {
-
-    foreach ($handles as $phid => $handle) {
-      $list = $objects[$phid];
-
-      $handle->setName($list->getName());
-      $handle->setURI($list->getURI());
-    }
-  }
-
-  public function canLoadNamedObject($name) {
-    return preg_match('/^.+@.+/', $name);
-  }
-
-  public function loadNamedObjects(
-    PhabricatorObjectQuery $query,
-    array $names) {
-
-    $id_map = array();
-    foreach ($names as $name) {
-      // Maybe normalize these some day?
-      $id = $name;
-      $id_map[$id][] = $name;
-    }
-
-    $objects = id(new PhabricatorMailingListQuery())
-      ->setViewer($query->getViewer())
-      ->withEmails(array_keys($id_map))
-      ->execute();
-
-    $results = array();
-    foreach ($objects as $id => $object) {
-      $email = $object->getEmail();
-      foreach (idx($id_map, $email, array()) as $name) {
-        $results[$name] = $object;
-      }
-    }
-
-    return $results;
-  }
-
-}
diff --git a/src/applications/mailinglists/query/PhabricatorMailingListQuery.php b/src/applications/mailinglists/query/PhabricatorMailingListQuery.php
deleted file mode 100644
--- a/src/applications/mailinglists/query/PhabricatorMailingListQuery.php
+++ /dev/null
@@ -1,86 +0,0 @@
-<?php
-
-final class PhabricatorMailingListQuery
-  extends PhabricatorCursorPagedPolicyAwareQuery {
-
-  private $phids;
-  private $ids;
-  private $emails;
-  private $names;
-
-  public function withIDs($ids) {
-    $this->ids = $ids;
-    return $this;
-  }
-
-  public function withPHIDs($phids) {
-    $this->phids = $phids;
-    return $this;
-  }
-
-  public function withEmails(array $emails) {
-    $this->emails = $emails;
-    return $this;
-  }
-
-  public function withNames(array $names) {
-    $this->names = $names;
-    return $this;
-  }
-
-  protected function loadPage() {
-    $table = new PhabricatorMetaMTAMailingList();
-    $conn_r = $table->establishConnection('r');
-
-    $data = queryfx_all(
-      $conn_r,
-      'SELECT * FROM %T %Q %Q %Q',
-      $table->getTableName(),
-      $this->buildWhereClause($conn_r),
-      $this->buildOrderClause($conn_r),
-      $this->buildLimitClause($conn_r));
-
-    return $table->loadAllFromArray($data);
-  }
-
-  protected function buildWhereClause(AphrontDatabaseConnection $conn_r) {
-    $where = array();
-
-    if ($this->ids) {
-      $where[] = qsprintf(
-        $conn_r,
-        'id IN (%Ld)',
-        $this->ids);
-    }
-
-    if ($this->phids) {
-      $where[] = qsprintf(
-        $conn_r,
-        'phid IN (%Ls)',
-        $this->phids);
-    }
-
-    if ($this->names) {
-      $where[] = qsprintf(
-        $conn_r,
-        'name IN (%Ls)',
-        $this->names);
-    }
-
-    if ($this->emails) {
-      $where[] = qsprintf(
-        $conn_r,
-        'email IN (%Ls)',
-        $this->emails);
-    }
-
-    $where[] = $this->buildPagingClause($conn_r);
-
-    return $this->formatWhereClause($where);
-  }
-
-  public function getQueryApplicationClass() {
-    return 'PhabricatorMailingListsApplication';
-  }
-
-}
diff --git a/src/applications/mailinglists/query/PhabricatorMailingListSearchEngine.php b/src/applications/mailinglists/query/PhabricatorMailingListSearchEngine.php
deleted file mode 100644
--- a/src/applications/mailinglists/query/PhabricatorMailingListSearchEngine.php
+++ /dev/null
@@ -1,91 +0,0 @@
-<?php
-
-final class PhabricatorMailingListSearchEngine
-  extends PhabricatorApplicationSearchEngine {
-
-  public function getResultTypeDescription() {
-    return pht('Mailing Lists');
-  }
-
-  public function getApplicationClassName() {
-    return 'PhabricatorMailingListsApplication';
-  }
-
-  public function buildSavedQueryFromRequest(AphrontRequest $request) {
-    $saved = new PhabricatorSavedQuery();
-
-    return $saved;
-  }
-
-  public function buildQueryFromSavedQuery(PhabricatorSavedQuery $saved) {
-    $query = id(new PhabricatorMailingListQuery());
-
-    return $query;
-  }
-
-  public function buildSearchForm(
-    AphrontFormView $form,
-    PhabricatorSavedQuery $saved_query) {
-
-    // This just makes it clear to the user that the lack of filters is
-    // intentional, not a bug.
-    $form->appendChild(
-      id(new AphrontFormMarkupControl())
-        ->setValue(pht('No query filters are available for mailing lists.')));
-  }
-
-  protected function getURI($path) {
-    return '/mailinglists/'.$path;
-  }
-
-  protected function getBuiltinQueryNames() {
-    return array(
-      'all' => pht('All Lists'),
-    );
-  }
-
-  public function buildSavedQueryFromBuiltin($query_key) {
-    $query = $this->newSavedQuery();
-    $query->setQueryKey($query_key);
-
-    switch ($query_key) {
-      case 'all':
-        return $query;
-    }
-
-    return parent::buildSavedQueryFromBuiltin($query_key);
-  }
-
-  protected function renderResultList(
-    array $lists,
-    PhabricatorSavedQuery $query,
-    array $handles) {
-    assert_instances_of($lists, 'PhabricatorMetaMTAMailingList');
-
-    $view = id(new PHUIObjectItemListView());
-
-    $can_manage = PhabricatorPolicyFilter::hasCapability(
-      $this->requireViewer(),
-      $this->getApplication(),
-      PhabricatorMailingListsManageCapability::CAPABILITY);
-
-    foreach ($lists as $list) {
-      $item = new PHUIObjectItemView();
-
-      $item->setHeader($list->getName());
-      $item->setHref($list->getURI());
-      $item->addAttribute($list->getEmail());
-      $item->addAction(
-        id(new PHUIListItemView())
-          ->setIcon('fa-pencil')
-          ->setHref($this->getApplicationURI('/edit/'.$list->getID().'/'))
-          ->setDisabled(!$can_manage)
-          ->setWorkflow(!$can_manage));
-
-      $view->addItem($item);
-    }
-
-    return $view;
-  }
-
-}
diff --git a/src/applications/mailinglists/storage/PhabricatorMetaMTAMailingList.php b/src/applications/mailinglists/storage/PhabricatorMetaMTAMailingList.php
deleted file mode 100644
--- a/src/applications/mailinglists/storage/PhabricatorMetaMTAMailingList.php
+++ /dev/null
@@ -1,77 +0,0 @@
-<?php
-
-final class PhabricatorMetaMTAMailingList extends PhabricatorMetaMTADAO
-  implements
-    PhabricatorPolicyInterface,
-    PhabricatorDestructibleInterface {
-
-  protected $name;
-  protected $email;
-  protected $uri;
-
-  public function generatePHID() {
-    return PhabricatorPHID::generateNewPHID(
-      PhabricatorMailingListListPHIDType::TYPECONST);
-  }
-
-  protected function getConfiguration() {
-    return array(
-      self::CONFIG_AUX_PHID => true,
-      self::CONFIG_COLUMN_SCHEMA => array(
-        'name' => 'text128',
-        'email' => 'text128',
-        'uri' => 'text255?',
-      ),
-      self::CONFIG_KEY_SCHEMA => array(
-        'key_phid' => null,
-        'phid' => array(
-          'columns' => array('phid'),
-          'unique' => true,
-        ),
-        'email' => array(
-          'columns' => array('email'),
-          'unique' => true,
-        ),
-        'name' => array(
-          'columns' => array('name'),
-          'unique' => true,
-        ),
-      ),
-    ) + parent::getConfiguration();
-  }
-
-
-/* -(  PhabricatorPolicyInterface  )----------------------------------------- */
-
-
-  public function getCapabilities() {
-    return array(
-      PhabricatorPolicyCapability::CAN_VIEW,
-    );
-  }
-
-  public function getPolicy($capability) {
-    return PhabricatorPolicies::getMostOpenPolicy();
-  }
-
-  public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
-    return false;
-  }
-
-  public function describeAutomaticCapability($capability) {
-    return null;
-  }
-
-
-/* -(  PhabricatorDestructibleInterface  )----------------------------------- */
-
-
-  public function destroyObjectPermanently(
-    PhabricatorDestructionEngine $engine) {
-
-    $this->openTransaction();
-    $this->delete();
-    $this->saveTransaction();
-  }
-
-}
diff --git a/src/applications/mailinglists/typeahead/PhabricatorMailingListDatasource.php b/src/applications/mailinglists/typeahead/PhabricatorMailingListDatasource.php
deleted file mode 100644
--- a/src/applications/mailinglists/typeahead/PhabricatorMailingListDatasource.php
+++ /dev/null
@@ -1,39 +0,0 @@
-<?php
-
-final class PhabricatorMailingListDatasource
-  extends PhabricatorTypeaheadDatasource {
-
-  public function getBrowseTitle() {
-    return pht('Browse Mailing Lists');
-  }
-
-  public function getPlaceholderText() {
-    return pht('Type a mailing list name...');
-  }
-
-  public function getDatasourceApplicationClass() {
-    return 'PhabricatorMailingListsApplication';
-  }
-
-  public function loadResults() {
-    $viewer = $this->getViewer();
-    $raw_query = $this->getRawQuery();
-
-    $query = id(new PhabricatorMailingListQuery());
-    $lists = $this->executeQuery($query);
-
-    $results = array();
-    foreach ($lists as $list) {
-      $results[] = id(new PhabricatorTypeaheadResult())
-        ->setName($list->getName())
-        ->setURI($list->getURI())
-        ->setPHID($list->getPHID());
-    }
-
-    // TODO: It would be slightly preferable to do this as part of the query,
-    // this is just simpler for the moment.
-
-    return $this->filterResultsAgainstTokens($results);
-  }
-
-}
diff --git a/src/applications/metamta/query/PhabricatorMetaMTAActorQuery.php b/src/applications/metamta/query/PhabricatorMetaMTAActorQuery.php
--- a/src/applications/metamta/query/PhabricatorMetaMTAActorQuery.php
+++ b/src/applications/metamta/query/PhabricatorMetaMTAActorQuery.php
@@ -39,9 +39,6 @@
         case PhabricatorPeopleExternalPHIDType::TYPECONST:
           $this->loadExternalUserActors($actors, $phids);
           break;
-        case PhabricatorMailingListListPHIDType::TYPECONST:
-          $this->loadMailingListActors($actors, $phids);
-          break;
         default:
           $this->loadUnknownActors($actors, $phids);
           break;
@@ -124,28 +121,6 @@
     }
   }
 
-  private function loadMailingListActors(array $actors, array $phids) {
-    assert_instances_of($actors, 'PhabricatorMetaMTAActor');
-
-    $lists = id(new PhabricatorMailingListQuery())
-      ->setViewer($this->getViewer())
-      ->withPHIDs($phids)
-      ->execute();
-    $lists = mpull($lists, null, 'getPHID');
-
-    foreach ($phids as $phid) {
-      $actor = $actors[$phid];
-
-      $list = idx($lists, $phid);
-      if (!$list) {
-        $actor->setUndeliverable(PhabricatorMetaMTAActor::REASON_UNLOADABLE);
-        continue;
-      }
-
-      $actor->setName($list->getName());
-      $actor->setEmailAddress($list->getEmail());
-    }
-  }
 
   private function loadUnknownActors(array $actors, array $phids) {
     foreach ($phids as $phid) {
diff --git a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
--- a/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
+++ b/src/applications/metamta/storage/PhabricatorMetaMTAReceivedMail.php
@@ -100,13 +100,7 @@
     }
     $users = id(new PhabricatorUserEmail())
       ->loadAllWhere('address IN (%Ls)', $addresses);
-    $user_phids = mpull($users, 'getUserPHID');
-
-    $mailing_lists = id(new PhabricatorMetaMTAMailingList())
-      ->loadAllWhere('email in (%Ls)', $addresses);
-    $mailing_list_phids = mpull($mailing_lists, 'getPHID');
-
-    return array_merge($user_phids,  $mailing_list_phids);
+    return mpull($users, 'getUserPHID');
   }
 
   public function processReceivedMail() {
diff --git a/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableDatasource.php b/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableDatasource.php
--- a/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableDatasource.php
+++ b/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableDatasource.php
@@ -19,7 +19,6 @@
     return array(
       new PhabricatorPeopleDatasource(),
       new PhabricatorProjectDatasource(),
-      new PhabricatorMailingListDatasource(),
     );
   }
 
diff --git a/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableFunctionDatasource.php b/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableFunctionDatasource.php
--- a/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableFunctionDatasource.php
+++ b/src/applications/metamta/typeahead/PhabricatorMetaMTAMailableFunctionDatasource.php
@@ -21,7 +21,6 @@
       new PhabricatorPeopleDatasource(),
       new PhabricatorProjectMembersDatasource(),
       new PhabricatorProjectDatasource(),
-      new PhabricatorMailingListDatasource(),
     );
   }
 
diff --git a/src/applications/phid/query/PhabricatorObjectListQuery.php b/src/applications/phid/query/PhabricatorObjectListQuery.php
--- a/src/applications/phid/query/PhabricatorObjectListQuery.php
+++ b/src/applications/phid/query/PhabricatorObjectListQuery.php
@@ -143,27 +143,6 @@
       }
     }
 
-    $mailing_list_app = PhabricatorApplication::getByClass(
-      'PhabricatorMailingListsApplication');
-    if ($mailing_list_app->isInstalled()) {
-      if ($names) {
-        // We still haven't been able to resolve everything; try mailing lists
-        // by name as a last resort.
-        $lists = id(new PhabricatorMailingListQuery())
-          ->setViewer($this->getViewer())
-          ->withNames($names)
-          ->execute();
-
-        $lists = mpull($lists, null, 'getName');
-        foreach ($names as $key => $name) {
-          if (isset($lists[$name])) {
-            $results[$name] = $lists[$name];
-            unset($names[$key]);
-          }
-        }
-      }
-    }
-
     return $results;
   }
 
diff --git a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
--- a/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
+++ b/src/applications/search/engine/PhabricatorApplicationSearchEngine.php
@@ -484,7 +484,6 @@
       $key,
       array(
         PhabricatorProjectProjectPHIDType::TYPECONST,
-        PhabricatorMailingListListPHIDType::TYPECONST,
       ));
   }
 
diff --git a/src/docs/book/phabricator.book b/src/docs/book/phabricator.book
--- a/src/docs/book/phabricator.book
+++ b/src/docs/book/phabricator.book
@@ -137,10 +137,6 @@
       "name": "Macro",
       "include": "(^src/applications/macro/)"
     },
-    "mailinglists": {
-      "name": "Mailing Lists",
-      "include": "(^src/applications/mailinglists/)"
-    },
     "maniphest": {
       "name": "Maniphest",
       "include": "(^src/applications/maniphest/)"