diff --git a/mozilla/mail/base/content/messenger.css b/mozilla/mail/base/content/messenger.css
index 4077024793a..034f73c99a7 100644
--- a/mozilla/mail/base/content/messenger.css
+++ b/mozilla/mail/base/content/messenger.css
@@ -161,6 +161,16 @@ dummy.usesMailWidgets {
   -moz-binding: url("chrome://messenger/content/mailWidgets.xml#searchpopup");
 }
 
+.folderSummaryPopup
+{
+  -moz-binding: url("chrome://messenger/content/mailWidgets.xml#folderSummary-popup");
+}
+
+folderSummaryMessage
+{
+  -moz-binding: url("chrome://messenger/content/mailWidgets.xml#folderSummary-message");
+}
+
 .foldersTree
 {
   margin: 0px;
diff --git a/mozilla/mail/base/content/messenger.xul b/mozilla/mail/base/content/messenger.xul
index e2c5752c2ac..60276c0f120 100644
--- a/mozilla/mail/base/content/messenger.xul
+++ b/mozilla/mail/base/content/messenger.xul
@@ -161,6 +161,8 @@
   </hbox>
 </popup>
 
+<tooltip id="folderpopup" class="folderSummaryPopup"/>
+
 <popup id="messagePaneContext"/>
 
   <toolbox id="mail-toolbox" class="toolbox-top">
@@ -184,6 +186,7 @@
             datasources="rdf:null"
             statedatasource="rdf:mailnewsfolders"
             flags="dont-build-content"
+            tooltip="folderpopup"
             ondraggesture="BeginDragFolderTree(event);"
             onselect="FolderPaneSelectionChange();">
         <template>
diff --git a/mozilla/mail/themes/pinstripe/mail/folderPane.css b/mozilla/mail/themes/pinstripe/mail/folderPane.css
index a151631edbc..6e86a53fe5f 100644
--- a/mozilla/mail/themes/pinstripe/mail/folderPane.css
+++ b/mozilla/mail/themes/pinstripe/mail/folderPane.css
@@ -133,3 +133,15 @@ treechildren::-moz-tree-cell-text(folderNameCol, noSelect-true) {
 .tree-folder-checkbox {
   list-style-image: none;
 }
+
+/* ::::: Folder Summary Popup ::::: */
+
+.folderSummary-subject {
+  font-weight: bold; 
+  max-width: 25em;
+}
+
+.folderSummary-previewText {
+  color: grey; 
+  max-width: 35em;
+}
diff --git a/mozilla/mail/themes/qute/mail/folderPane.css b/mozilla/mail/themes/qute/mail/folderPane.css
index 169bf55e1bb..4e95040bc0e 100644
--- a/mozilla/mail/themes/qute/mail/folderPane.css
+++ b/mozilla/mail/themes/qute/mail/folderPane.css
@@ -143,4 +143,16 @@ treechildren::-moz-tree-cell-text(folderNameCol, noSelect-true) {
 
 .tree-folder-checkbox {
   list-style-image: none;
-}
\ No newline at end of file
+}
+
+/* ::::: Folder Summary Popup ::::: */
+
+.folderSummary-subject {
+  font-weight: bold; 
+  max-width: 25em;
+}
+
+.folderSummary-previewText {
+  color: grey; 
+  max-width: 35em;
+}
diff --git a/mozilla/mailnews/base/resources/content/mailWidgets.xml b/mozilla/mailnews/base/resources/content/mailWidgets.xml
index c7c1f6eabf4..407c84245e9 100644
--- a/mozilla/mailnews/base/resources/content/mailWidgets.xml
+++ b/mozilla/mailnews/base/resources/content/mailWidgets.xml
@@ -1978,4 +1978,107 @@
     </xbl:content>
   </binding>
 
+  <binding id="folderSummary-popup" extends="chrome://global/content/bindings/popup.xml#tooltip">
+    <content>
+      <children>
+        <xul:vbox/>
+      </children>
+    </content>
+    
+    <implementation>
+      <field name="mMaxMsgHdrsInPopup">8</field>
+    </implementation>
+
+    <handlers>
+      <handler event="popupshowing">
+        <![CDATA[
+          var folderTree = GetFolderTree();
+          var row = folderTree.treeBoxObject.getRowAt(event.clientX, event.clientY);
+          if (row == -1)
+            return false;
+
+          var msgFolder = GetFolderResource(folderTree, row).QueryInterface(Components.interfaces.nsIMsgFolder);
+          if (!msgFolder || msgFolder.isServer) 
+            return false;
+          
+          // now get the database
+          var msgDatabase = msgFolder.getMsgDatabase(msgWindow);
+          var msgKeys = {};
+          var numMsgKeys = {};
+          msgDatabase.getNewList(numMsgKeys, msgKeys);
+
+          if (!numMsgKeys.value)
+            return false;
+
+          // fetchMsgPreviewText forces the previewText property to get generated
+          // for each of the message keys.
+          var asyncResults = {};
+
+          try {
+            msgFolder.fetchMsgPreviewText(msgKeys.value, numMsgKeys.value, false, null, asyncResults); 
+          }
+          catch (ex)
+          {
+            // fetchMsgPreviewText throws an error when we call it on a news folder, we should just not show
+            // the tooltip if this method returns an error.
+            dump('fetchMsgPreviewText threw an error or failed to set any preview text data\n');
+            return false; 
+          }
+
+          var index = 0;
+          while (index < this.mMaxMsgHdrsInPopup && index < numMsgKeys.value)
+          {
+            var msgPopup = document.createElementNS("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul", "folderSummaryMessage");
+            // hack to work around the fact that the xbl binding from createElementNS is asynch. 
+            setTimeout(function(aMsgPopup, aMsgHdr) {
+                      aMsgPopup.init(aMsgHdr); }, 0, 
+			                msgPopup, msgDatabase.GetMsgHdrForKey(msgKeys.value[index++])); 
+
+            document.getAnonymousNodes(this)[0].appendChild(msgPopup);
+          }            
+          return true;
+        ]]>
+      </handler>
+
+      <handler event="popuphiding">
+        <![CDATA[
+          var containingBox = document.getAnonymousNodes(this)[0];
+          while (containingBox.hasChildNodes()) 
+            containingBox.removeChild(containingBox.lastChild);          
+        ]]>
+      </handler>
+    </handlers>
+  </binding>
+
+  <binding id="folderSummary-message">
+    <content>
+      <xul:vbox>
+        <xul:hbox>
+          <xul:label class="folderSummary-subject" xbl:inherits="value=subject,crop" crop="right"/>
+          <xul:label class="folderSummary-sender" xbl:inherits="value=sender" crop="right"/>
+        </xul:hbox>
+        <xul:description class="folderSummary-previewText" xbl:inherits="value=previewText" crop="right"></xul:description>
+      </xul:vbox>
+    </content>
+    <implementation>
+      <method name="init">
+        <parameter name="aMsgHdr"/>
+        <body>
+          <![CDATA[
+            this.setAttribute('subject', aMsgHdr.mime2DecodedSubject);
+            // TO DO: worry about character set conversions
+            var previewText = aMsgHdr.getStringProperty('preview'); // replace tabs, line returns, etc. with a space
+            if (previewText)
+              this.setAttribute('previewText',  previewText);
+
+            var hdrParser = Components.classes["@mozilla.org/messenger/headerparser;1"].getService(Components.interfaces.nsIMsgHeaderParser);
+            var names = {};
+            var emails = {};
+            var numAddresses = hdrParser.parseHeadersWithArray(aMsgHdr.mime2DecodedAuthor, emails, names, {});
+            this.setAttribute('sender', ' - ' + (names.value[0] ? names.value[0] : emails.value[0]));
+          ]]>
+        </body>
+      </method>
+    </implementation>
+  </binding>
 </bindings>
diff --git a/mozilla/mailnews/base/util/nsMsgDBFolder.cpp b/mozilla/mailnews/base/util/nsMsgDBFolder.cpp
index 82298d418a0..a94f4da3204 100644
--- a/mozilla/mailnews/base/util/nsMsgDBFolder.cpp
+++ b/mozilla/mailnews/base/util/nsMsgDBFolder.cpp
@@ -5143,6 +5143,7 @@ nsresult nsMsgDBFolder::GetMsgPreviewTextFromStream(nsIMsgDBHdr *msgHdr, nsIInpu
         if (!boundary.IsEmpty() && boundary.Equals(curLine))
           break;
         msgBody.Append(curLine);
+        msgBody.Append(" "); // convert each end of line delimter into a space
         // how much html should we parse for text? 2K? 4K?
         if (msgBody.Length() > 2048 || (!msgBodyIsHtml && msgBody.Length() > 255))
           break;