diff --git a/src/applications/paste/editor/PhabricatorPasteEditor.php b/src/applications/paste/editor/PhabricatorPasteEditor.php
--- a/src/applications/paste/editor/PhabricatorPasteEditor.php
+++ b/src/applications/paste/editor/PhabricatorPasteEditor.php
@@ -153,6 +153,17 @@
     );
   }
 
+  public function getMailTagsMap() {
+    return array(
+      PhabricatorPasteTransaction::MAILTAG_CONTENT =>
+        pht('Paste title, language or text changes.'),
+      PhabricatorPasteTransaction::MAILTAG_COMMENT =>
+        pht('Someone comments on a paste.'),
+      PhabricatorPasteTransaction::MAILTAG_OTHER =>
+        pht('Other paste activity not listed above occurs.'),
+    );
+  }
+
   protected function buildReplyHandler(PhabricatorLiskDAO $object) {
     return id(new PasteReplyHandler())
       ->setMailReceiver($object);
diff --git a/src/applications/paste/storage/PhabricatorPasteTransaction.php b/src/applications/paste/storage/PhabricatorPasteTransaction.php
--- a/src/applications/paste/storage/PhabricatorPasteTransaction.php
+++ b/src/applications/paste/storage/PhabricatorPasteTransaction.php
@@ -7,6 +7,10 @@
   const TYPE_TITLE = 'paste.title';
   const TYPE_LANGUAGE = 'paste.language';
 
+  const MAILTAG_CONTENT = 'paste-content';
+  const MAILTAG_OTHER = 'paste-other';
+  const MAILTAG_COMMENT = 'paste-comment';
+
   public function getApplicationName() {
     return 'pastebin';
   }
@@ -182,4 +186,22 @@
     return parent::renderChangeDetails($viewer);
   }
 
+  public function getMailTags() {
+    $tags = array();
+    switch ($this->getTransactionType()) {
+      case self::TYPE_TITLE:
+      case self::TYPE_CONTENT:
+      case self::TYPE_LANGUAGE:
+        $tags[] = self::MAILTAG_CONTENT;
+        break;
+      case PhabricatorTransactions::TYPE_COMMENT:
+        $tags[] = self::MAILTAG_COMMENT;
+        break;
+      default:
+        $tags[] = self::MAILTAG_OTHER;
+        break;
+    }
+    return $tags;
+  }
+
 }