diff --git a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
--- a/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ b/src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -2969,34 +2969,62 @@
     $object_label = null,
     $object_href = null) {
 
+    // First, remove transactions which shouldn't be rendered in mail.
+    foreach ($xactions as $key => $xaction) {
+      if ($xaction->shouldHideForMail($xactions)) {
+        unset($xactions[$key]);
+      }
+    }
+
     $headers = array();
     $headers_html = array();
     $comments = array();
     $details = array();
 
+    $seen_comment = false;
     foreach ($xactions as $xaction) {
-      if ($xaction->shouldHideForMail($xactions)) {
-        continue;
-      }
 
-      $header = $xaction->getTitleForMail();
-      if ($header !== null) {
-        $headers[] = $header;
-      }
+      // Most mail has zero or one comments. In these cases, we render the
+      // "alice added a comment." transaction in the header, like a normal
+      // transaction.
 
-      $header_html = $xaction->getTitleForHTMLMail();
-      if ($header_html !== null) {
-        $headers_html[] = $header_html;
-      }
+      // Some mail, like Differential undraft mail or "!history" mail, may
+      // have two or more comments. In these cases, we'll put the first
+      // "alice added a comment." transaction in the header normally, but
+      // move the other transactions down so they provide context above the
+      // actual comment.
 
       $comment = $xaction->getBodyForMail();
       if ($comment !== null) {
-        $comments[] = $comment;
+        $is_comment = true;
+        $comments[] = array(
+          'xaction' => $xaction,
+          'comment' => $comment,
+          'initial' => !$seen_comment,
+        );
+      } else {
+        $is_comment = false;
+      }
+
+      if (!$is_comment || !$seen_comment) {
+        $header = $xaction->getTitleForMail();
+        if ($header !== null) {
+          $headers[] = $header;
+        }
+
+        $header_html = $xaction->getTitleForHTMLMail();
+        if ($header_html !== null) {
+          $headers_html[] = $header_html;
+        }
       }
 
       if ($xaction->hasChangeDetailsForMail()) {
         $details[] = $xaction;
       }
+
+      if ($is_comment) {
+        $seen_comment = true;
+      }
     }
 
     $headers_text = implode("\n", $headers);
@@ -3029,8 +3057,7 @@
         $object_label);
     }
 
-    $xactions_style = array(
-    );
+    $xactions_style = array();
 
     $header_action = phutil_tag(
       'td',
@@ -3057,7 +3084,25 @@
 
     $body->addRawHTMLSection($headers_html);
 
-    foreach ($comments as $comment) {
+    foreach ($comments as $spec) {
+      $xaction = $spec['xaction'];
+      $comment = $spec['comment'];
+      $is_initial = $spec['initial'];
+
+      // If this is not the first comment in the mail, add the header showing
+      // who wrote the comment immediately above the comment.
+      if (!$is_initial) {
+        $header = $xaction->getTitleForMail();
+        if ($header !== null) {
+          $body->addRawPlaintextSection($header);
+        }
+
+        $header_html = $xaction->getTitleForHTMLMail();
+        if ($header_html !== null) {
+          $body->addRawHTMLSection($header_html);
+        }
+      }
+
       $body->addRemarkupSection(null, $comment);
     }