diff --git a/src/applications/ponder/editor/PonderQuestionEditor.php b/src/applications/ponder/editor/PonderQuestionEditor.php
index d9f77fad94..eeac4b3414 100644
--- a/src/applications/ponder/editor/PonderQuestionEditor.php
+++ b/src/applications/ponder/editor/PonderQuestionEditor.php
@@ -212,6 +212,19 @@ final class PonderQuestionEditor
     return true;
   }
 
+  public function getMailTagsMap() {
+    return array(
+      PonderQuestionTransaction::MAILTAG_DETAILS =>
+        pht('Someone changes the questions details.'),
+      PonderQuestionTransaction::MAILTAG_ANSWERS =>
+        pht('Someone adds a new answer.'),
+      PonderQuestionTransaction::MAILTAG_COMMENT =>
+        pht('Someone comments on the question.'),
+      PonderQuestionTransaction::MAILTAG_OTHER =>
+        pht('Other question activity not listed above occurs.'),
+    );
+  }
+
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new PonderQuestionReplyHandler())
       ->setMailReceiver($object);
diff --git a/src/applications/ponder/storage/PonderQuestionTransaction.php b/src/applications/ponder/storage/PonderQuestionTransaction.php
index 80cb9f83f0..3c2734ea71 100644
--- a/src/applications/ponder/storage/PonderQuestionTransaction.php
+++ b/src/applications/ponder/storage/PonderQuestionTransaction.php
@@ -8,6 +8,11 @@ final class PonderQuestionTransaction
   const TYPE_ANSWERS = 'ponder.question:answer';
   const TYPE_STATUS = 'ponder.question:status';
 
+  const MAILTAG_DETAILS = 'question:details';
+  const MAILTAG_COMMENT = 'question:comment';
+  const MAILTAG_ANSWERS = 'question:answer';
+  const MAILTAG_OTHER = 'question:other';
+
   public function getApplicationName() {
     return 'ponder';
   }
@@ -105,6 +110,28 @@ final class PonderQuestionTransaction
     return parent::getTitle();
   }
 
+  public function getMailTags() {
+    $tags = parent::getMailTags();
+
+    switch ($this->getTransactionType()) {
+      case PhabricatorTransactions::TYPE_COMMENT:
+        $tags[] = self::MAILTAG_COMMENT;
+        break;
+      case self::TYPE_TITLE:
+      case self::TYPE_CONTENT:
+      case self::TYPE_STATUS:
+        $tags[] = self::MAILTAG_DETAILS;
+        break;
+      case self::TYPE_ANSWERS:
+        $tags[] = self::MAILTAG_ANSWERS;
+        break;
+      default:
+        $tags[] = self::MAILTAG_OTHER;
+        break;
+    }
+    return $tags;
+  }
+
   public function getIcon() {
     $old = $this->getOldValue();
     $new = $this->getNewValue();