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
@@ -2212,6 +2212,7 @@
     'PhabricatorAuthContactNumberPrimaryTransaction' => 'applications/auth/xaction/PhabricatorAuthContactNumberPrimaryTransaction.php',
     'PhabricatorAuthContactNumberQuery' => 'applications/auth/query/PhabricatorAuthContactNumberQuery.php',
     'PhabricatorAuthContactNumberStatusTransaction' => 'applications/auth/xaction/PhabricatorAuthContactNumberStatusTransaction.php',
+    'PhabricatorAuthContactNumberTestController' => 'applications/auth/controller/contact/PhabricatorAuthContactNumberTestController.php',
     'PhabricatorAuthContactNumberTransaction' => 'applications/auth/storage/PhabricatorAuthContactNumberTransaction.php',
     'PhabricatorAuthContactNumberTransactionQuery' => 'applications/auth/query/PhabricatorAuthContactNumberTransactionQuery.php',
     'PhabricatorAuthContactNumberTransactionType' => 'applications/auth/xaction/PhabricatorAuthContactNumberTransactionType.php',
@@ -2368,6 +2369,7 @@
     'PhabricatorAuthTemporaryTokenType' => 'applications/auth/tokentype/PhabricatorAuthTemporaryTokenType.php',
     'PhabricatorAuthTemporaryTokenTypeModule' => 'applications/auth/tokentype/PhabricatorAuthTemporaryTokenTypeModule.php',
     'PhabricatorAuthTerminateSessionController' => 'applications/auth/controller/PhabricatorAuthTerminateSessionController.php',
+    'PhabricatorAuthTestSMSAction' => 'applications/auth/action/PhabricatorAuthTestSMSAction.php',
     'PhabricatorAuthTryFactorAction' => 'applications/auth/action/PhabricatorAuthTryFactorAction.php',
     'PhabricatorAuthUnlinkController' => 'applications/auth/controller/PhabricatorAuthUnlinkController.php',
     'PhabricatorAuthValidateController' => 'applications/auth/controller/PhabricatorAuthValidateController.php',
@@ -7924,6 +7926,7 @@
     'PhabricatorAuthContactNumberPrimaryTransaction' => 'PhabricatorAuthContactNumberTransactionType',
     'PhabricatorAuthContactNumberQuery' => 'PhabricatorCursorPagedPolicyAwareQuery',
     'PhabricatorAuthContactNumberStatusTransaction' => 'PhabricatorAuthContactNumberTransactionType',
+    'PhabricatorAuthContactNumberTestController' => 'PhabricatorAuthContactNumberController',
     'PhabricatorAuthContactNumberTransaction' => 'PhabricatorModularTransaction',
     'PhabricatorAuthContactNumberTransactionQuery' => 'PhabricatorApplicationTransactionQuery',
     'PhabricatorAuthContactNumberTransactionType' => 'PhabricatorModularTransactionType',
@@ -8116,6 +8119,7 @@
     'PhabricatorAuthTemporaryTokenType' => 'Phobject',
     'PhabricatorAuthTemporaryTokenTypeModule' => 'PhabricatorConfigModule',
     'PhabricatorAuthTerminateSessionController' => 'PhabricatorAuthController',
+    'PhabricatorAuthTestSMSAction' => 'PhabricatorSystemAction',
     'PhabricatorAuthTryFactorAction' => 'PhabricatorSystemAction',
     'PhabricatorAuthUnlinkController' => 'PhabricatorAuthController',
     'PhabricatorAuthValidateController' => 'PhabricatorAuthController',
diff --git a/src/applications/auth/action/PhabricatorAuthTestSMSAction.php b/src/applications/auth/action/PhabricatorAuthTestSMSAction.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/action/PhabricatorAuthTestSMSAction.php
@@ -0,0 +1,22 @@
+<?php
+
+final class PhabricatorAuthTestSMSAction extends PhabricatorSystemAction {
+
+  const TYPECONST = 'auth.sms.test';
+
+  public function getActionConstant() {
+    return self::TYPECONST;
+  }
+
+  public function getScoreThreshold() {
+    return 60 / phutil_units('1 hour in seconds');
+  }
+
+  public function getLimitExplanation() {
+    return pht(
+      'You and other users on this install are collectively sending too '.
+      'many test text messages too quickly. Wait a few minutes to continue '.
+      'textings tests.');
+  }
+
+}
diff --git a/src/applications/auth/application/PhabricatorAuthApplication.php b/src/applications/auth/application/PhabricatorAuthApplication.php
--- a/src/applications/auth/application/PhabricatorAuthApplication.php
+++ b/src/applications/auth/application/PhabricatorAuthApplication.php
@@ -115,6 +115,8 @@
             'PhabricatorAuthContactNumberDisableController',
           'primary/(?P<id>[1-9]\d*)/' =>
             'PhabricatorAuthContactNumberPrimaryController',
+          'test/(?P<id>[1-9]\d*)/' =>
+            'PhabricatorAuthContactNumberTestController',
         ),
       ),
 
diff --git a/src/applications/auth/controller/contact/PhabricatorAuthContactNumberTestController.php b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberTestController.php
new file mode 100644
--- /dev/null
+++ b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberTestController.php
@@ -0,0 +1,65 @@
+<?php
+
+final class PhabricatorAuthContactNumberTestController
+  extends PhabricatorAuthContactNumberController {
+
+  public function handleRequest(AphrontRequest $request) {
+    $viewer = $request->getViewer();
+    $id = $request->getURIData('id');
+
+    $number = id(new PhabricatorAuthContactNumberQuery())
+      ->setViewer($viewer)
+      ->withIDs(array($id))
+      ->requireCapabilities(
+        array(
+          PhabricatorPolicyCapability::CAN_VIEW,
+          PhabricatorPolicyCapability::CAN_EDIT,
+        ))
+      ->executeOne();
+    if (!$number) {
+      return new Aphront404Response();
+    }
+
+    $id = $number->getID();
+    $cancel_uri = $number->getURI();
+
+    // NOTE: This is a global limit shared by all users.
+    PhabricatorSystemActionEngine::willTakeAction(
+      array(id(new PhabricatorAuthApplication())->getPHID()),
+      new PhabricatorAuthTestSMSAction(),
+      1);
+
+    if ($request->isFormPost()) {
+      $uri = PhabricatorEnv::getURI('/');
+      $uri = new PhutilURI($uri);
+
+      $mail = id(new PhabricatorMetaMTAMail())
+        ->setMessageType(PhabricatorMailSMSMessage::MESSAGETYPE)
+        ->addTos(array($viewer->getPHID()))
+        ->setForceDelivery(true)
+        ->setSensitiveContent(true)
+        ->setBody(
+          pht(
+            'This is a terse test text message from Phabricator (%s).',
+            $uri->getDomain()))
+        ->save();
+
+      return id(new AphrontRedirectResponse())->setURI($mail->getURI());
+    }
+
+    $number_display = phutil_tag(
+      'strong',
+      array(),
+      $number->getDisplayName());
+
+    return $this->newDialog()
+      ->setTitle(pht('Set Test Message'))
+      ->appendParagraph(
+        pht(
+          'Send a test message to %s?',
+          $number_display))
+      ->addSubmitButton(pht('Send SMS'))
+      ->addCancelButton($cancel_uri);
+  }
+
+}
diff --git a/src/applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php
--- a/src/applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php
+++ b/src/applications/auth/controller/contact/PhabricatorAuthContactNumberViewController.php
@@ -98,6 +98,14 @@
         ->setDisabled(!$can_edit)
         ->setWorkflow(!$can_edit));
 
+    $curtain->addAction(
+      id(new PhabricatorActionView())
+        ->setName(pht('Send Test Message'))
+        ->setIcon('fa-envelope-o')
+        ->setHref($this->getApplicationURI("contact/test/{$id}/"))
+        ->setDisabled(!$can_edit)
+        ->setWorkflow(true));
+
     if ($number->isDisabled()) {
       $disable_uri = $this->getApplicationURI("contact/enable/{$id}/");
       $disable_name = pht('Enable Contact Number');
diff --git a/src/applications/metamta/controller/PhabricatorMetaMTAMailViewController.php b/src/applications/metamta/controller/PhabricatorMetaMTAMailViewController.php
--- a/src/applications/metamta/controller/PhabricatorMetaMTAMailViewController.php
+++ b/src/applications/metamta/controller/PhabricatorMetaMTAMailViewController.php
@@ -187,6 +187,9 @@
       ->setStacked(true);
 
     $headers = $mail->getDeliveredHeaders();
+    if (!$headers) {
+      $headers = array();
+    }
 
     // Sort headers by name.
     $headers = isort($headers, 0);