diff --git a/mail/base/content/mailWindowOverlay.js b/mail/base/content/mailWindowOverlay.js
index d2203efefe6..dce593e7afc 100644
--- a/mail/base/content/mailWindowOverlay.js
+++ b/mail/base/content/mailWindowOverlay.js
@@ -493,24 +493,44 @@ function RemoveAllMessageTags()
   var selectedMsgUris = GetSelectedMessages();
   if (!selectedMsgUris.length)
     return;
-    
-  var msg = Components.classes["@mozilla.org/supports-array;1"]
-                          .createInstance(Components.interfaces.nsISupportsArray);
-                          
+
+  var messages = Components.classes["@mozilla.org/supports-array;1"]
+                           .createInstance(Components.interfaces.nsISupportsArray);
+  var tagService = Components.classes["@mozilla.org/messenger/tagservice;1"]
+                             .getService(Components.interfaces.nsIMsgTagService);
+  var tagArray = tagService.getAllTags({});
+
+  var allKeys = "";
+  for (j = 0; j < tagArray.length; ++j)
+  {
+    if (j)
+      allKeys += " ";
+    allKeys += tagArray[j].key;
+  }
+
+  var prevHdrFolder = null;
+  // this crudely handles cross-folder virtual folders with selected messages
+  // that spans folders, by coalescing consecutive messages in the selection
+  // that happen to be in the same folder. nsMsgSearchDBView does this better,
+  // but nsIMsgDBView doesn't handle commands with arguments, and untag takes a
+  // key argument. Furthermore, we only delete legacy labels and known tags,
+  // keeping other keywords like (non)junk intact.
+  var j;
   for (var i = 0; i < selectedMsgUris.length; ++i)
   {
-    // remove all tags by removing all their tag keys, all at once.
-    // (using a msgHdr's setStringProperty won't notify the threadPane!)
     var msgHdr = messenger.msgHdrFromURI(selectedMsgUris[i]);
     msgHdr.label = 0; // remove legacy label
-    msg.Clear();
-    msg.AppendElement(msgHdr);
-    
-    var keywords = msgHdr.getStringProperty("keywords");
-    // this will remove all keywords at once...
-    if (keywords.length > 0)
-      msgHdr.folder.removeKeywordFromMessages(msg, keywords);
+    if (prevHdrFolder != msgHdr.folder)
+    {
+      if (prevHdrFolder)
+        prevHdrFolder.removeKeywordsFromMessages(messages, allKeys);
+      messages.Clear();
+      prevHdrFolder = msgHdr.folder;
+    }
+    messages.AppendElement(msgHdr);
   }
+  if (prevHdrFolder)
+    prevHdrFolder.removeKeywordsFromMessages(messages, allKeys);
   OnTagsChange();
 }
 
@@ -554,7 +574,7 @@ function ToggleMessageTag(key, addKey)
   var msg = Components.classes["@mozilla.org/supports-array;1"]
                           .createInstance(Components.interfaces.nsISupportsArray);
   var selectedMsgUris = GetSelectedMessages();
-  var toggler = addKey ? "addKeywordToMessages" : "removeKeywordFromMessages";
+  var toggler = addKey ? "addKeywordsToMessages" : "removeKeywordsFromMessages";
   var prevHdrFolder = null;
   // this crudely handles cross-folder virtual folders with selected messages
   // that spans folders, by coalescing consecutive msgs in the selection
@@ -571,7 +591,7 @@ function ToggleMessageTag(key, addKey)
       // because resetting a label doesn't update the tree anymore...
       msg.Clear();
       msg.AppendElement(msgHdr);
-      msgHdr.folder.addKeywordToMessages(msg, "$label" + msgHdr.label);
+      msgHdr.folder.addKeywordsToMessages(msg, "$label" + msgHdr.label);
       msgHdr.label = 0; // remove legacy label
     }
     if (prevHdrFolder != msgHdr.folder)
diff --git a/mailnews/base/public/nsIMsgFolder.idl b/mailnews/base/public/nsIMsgFolder.idl
index 5c580d26e64..e0fb23d3833 100644
--- a/mailnews/base/public/nsIMsgFolder.idl
+++ b/mailnews/base/public/nsIMsgFolder.idl
@@ -71,7 +71,7 @@ typedef long nsMsgBiffState;
 // enumerated type for determining if a message has been replied to, forwarded, etc.
 typedef long nsMsgDispositionState;
 
-[scriptable, uuid(913D683A-206F-4c91-9B10-3FC4CAEA644E)]
+[scriptable, uuid(83d2454c-632e-4d6e-900a-7236a6d2aa9a)]
 interface nsIMsgFolder : nsICollection {
 
 const nsMsgBiffState nsMsgBiffState_NewMail = 0; // User has new mail waiting.
@@ -495,9 +495,9 @@ const nsMsgBiffState nsMsgBiffState_Unknown = 2; // We dunno whether there is ne
 
   // used to set/clear tags - we could have a single method to setKeywords which
   // would figure out the diffs, but these methods might be more convenient.
-  void addKeywordToMessages(in nsISupportsArray aMessages, in string aKeyword);
-  void removeKeywordFromMessages(in nsISupportsArray aMessages, in string aKeyword);
-
+  // keywords are space delimited, in the case of multiple keywords
+  void addKeywordsToMessages(in nsISupportsArray aMessages, in string aKeywords);
+  void removeKeywordsFromMessages(in nsISupportsArray aMessages, in string aKeywords);
   /**
    * Extract the message preview text from aStream, storing it as a string property
    * on aMsgHdr.
diff --git a/mailnews/base/resources/content/mailWindowOverlay.js b/mailnews/base/resources/content/mailWindowOverlay.js
index e3312dd9d91..1a4ae5d9182 100644
--- a/mailnews/base/resources/content/mailWindowOverlay.js
+++ b/mailnews/base/resources/content/mailWindowOverlay.js
@@ -473,16 +473,44 @@ function RemoveAllMessageTags()
   var selectedMsgUris = GetSelectedMessages();
   if (!selectedMsgUris.length)
     return;
-    
+
+  var messages = Components.classes["@mozilla.org/supports-array;1"]
+                           .createInstance(Components.interfaces.nsISupportsArray);
+  var tagService = Components.classes["@mozilla.org/messenger/tagservice;1"]
+                             .getService(Components.interfaces.nsIMsgTagService);
+  var tagArray = tagService.getAllTags({});
+
+  var allKeys = "";
+  for (j = 0; j < tagArray.length; ++j)
+  {
+    if (j)
+      allKeys += " ";
+    allKeys += tagArray[j].key;
+  }
+
+  var prevHdrFolder = null;
+  // this crudely handles cross-folder virtual folders with selected messages
+  // that spans folders, by coalescing consecutive messages in the selection
+  // that happen to be in the same folder. nsMsgSearchDBView does this better,
+  // but nsIMsgDBView doesn't handle commands with arguments, and untag takes a
+  // key argument. Furthermore, we only delete legacy labels and known tags,
+  // keeping other keywords like (non)junk intact.
+  var j;
   for (var i = 0; i < selectedMsgUris.length; ++i)
   {
-    // remove all tags by removing all their tag keys at once
-    // (using a msgHdr's setStringProperty won't notify the threadPane!)
     var msgHdr = messenger.msgHdrFromURI(selectedMsgUris[i]);
     msgHdr.label = 0; // remove legacy label
-    msgHdr.folder.getMsgDatabase(msgWindow)
-          .setStringProperty(msgHdr.messageKey, "keywords", "");
+    if (prevHdrFolder != msgHdr.folder)
+    {
+      if (prevHdrFolder)
+        prevHdrFolder.removeKeywordsFromMessages(messages, allKeys);
+      messages.Clear();
+      prevHdrFolder = msgHdr.folder;
+    }
+    messages.AppendElement(msgHdr);
   }
+  if (prevHdrFolder)
+    prevHdrFolder.removeKeywordsFromMessages(messages, allKeys);
   OnTagsChange();
 }
 
@@ -547,7 +575,7 @@ function ToggleMessageTag(key, addKey)
   var msg = Components.classes["@mozilla.org/supports-array;1"]
                           .createInstance(Components.interfaces.nsISupportsArray);
   var selectedMsgUris = GetSelectedMessages();
-  var toggler = addKey ? "addKeywordToMessages" : "removeKeywordFromMessages";
+  var toggler = addKey ? "addKeywordsToMessages" : "removeKeywordsFromMessages";
   var prevHdrFolder = null;
   // this crudely handles cross-folder virtual folders with selected messages
   // that spans folders, by coalescing consecutive msgs in the selection
@@ -564,7 +592,7 @@ function ToggleMessageTag(key, addKey)
       // because resetting a label doesn't update the tree anymore...
       msg.Clear();
       msg.AppendElement(msgHdr);
-      msgHdr.folder.addKeywordToMessages(msg, "$label" + msgHdr.label);
+      msgHdr.folder.addKeywordsToMessages(msg, "$label" + msgHdr.label);
       msgHdr.label = 0; // remove legacy label
     }
     if (prevHdrFolder != msgHdr.folder)
diff --git a/mailnews/base/search/src/nsMsgFilterService.cpp b/mailnews/base/search/src/nsMsgFilterService.cpp
index 4fe5a6a9b19..6ee7aee96c4 100644
--- a/mailnews/base/search/src/nsMsgFilterService.cpp
+++ b/mailnews/base/search/src/nsMsgFilterService.cpp
@@ -651,7 +651,7 @@ nsresult nsMsgFilterAfterTheFact::ApplyFilter()
         {
             nsXPIDLCString keyword;
             filterAction->GetStrValue(getter_Copies(keyword));
-            m_curFolder->AddKeywordToMessages(m_searchHitHdrs, keyword.get());
+            m_curFolder->AddKeywordsToMessages(m_searchHitHdrs, keyword.get());
         }
         break;
       case nsMsgFilterAction::JunkScore:
diff --git a/mailnews/base/util/nsMsgDBFolder.cpp b/mailnews/base/util/nsMsgDBFolder.cpp
index 2bfbcd74c3a..a73f31b6084 100644
--- a/mailnews/base/util/nsMsgDBFolder.cpp
+++ b/mailnews/base/util/nsMsgDBFolder.cpp
@@ -5469,7 +5469,7 @@ void nsMsgDBFolder::SetMRUTime()
 }
 
 
-NS_IMETHODIMP nsMsgDBFolder::AddKeywordToMessages(nsISupportsArray *aMessages, const char *aKeyword)
+NS_IMETHODIMP nsMsgDBFolder::AddKeywordsToMessages(nsISupportsArray *aMessages, const char *aKeywords)
 {
   nsresult rv = NS_OK;
   GetDatabase(nsnull);
@@ -5489,20 +5489,25 @@ NS_IMETHODIMP nsMsgDBFolder::AddKeywordToMessages(nsISupportsArray *aMessages, c
       (void) message->GetMessageKey(&msgKey);
 
       message->GetStringProperty("keywords", getter_Copies(keywords));
-      nsACString::const_iterator start, end;
-      if (!MsgFindKeyword(nsDependentCString(aKeyword), keywords, start, end))
+      nsCStringArray keywordArray;
+      keywordArray.ParseString(aKeywords, " ");
+      for (PRInt32 j = 0; j < keywordArray.Count(); j++)
       {
-        if (!keywords.IsEmpty())
-          keywords.Append(' ');
-        keywords.Append(aKeyword);
-        mDatabase->SetStringProperty(msgKey, "keywords", keywords);
+        nsACString::const_iterator start, end;
+        if (!MsgFindKeyword(*(keywordArray[j]), keywords, start, end))
+        {
+          if (!keywords.IsEmpty())
+            keywords.Append(' ');
+          keywords.Append(keywordArray[j]->get());
+        }
       }
+      mDatabase->SetStringProperty(msgKey, "keywords", keywords);
     }
   }
   return rv;
 }
 
-NS_IMETHODIMP nsMsgDBFolder::RemoveKeywordFromMessages(nsISupportsArray *aMessages, const char *aKeyword)
+NS_IMETHODIMP nsMsgDBFolder::RemoveKeywordsFromMessages(nsISupportsArray *aMessages, const char *aKeywords)
 {
   nsresult rv = NS_OK;
   GetDatabase(nsnull);
@@ -5514,7 +5519,6 @@ NS_IMETHODIMP nsMsgDBFolder::RemoveKeywordFromMessages(nsISupportsArray *aMessag
     NS_ENSURE_SUCCESS(rv, rv);
     nsXPIDLCString keywords;
     // If the tag is also a label, we should remove the label too...
-    PRBool keywordIsLabel = (!PL_strncasecmp(aKeyword, "$label", 6)  && aKeyword[6] >= '1' && aKeyword[6] <= '5');
 
     for(PRUint32 i = 0; i < count; i++)
     {
@@ -5522,31 +5526,38 @@ NS_IMETHODIMP nsMsgDBFolder::RemoveKeywordFromMessages(nsISupportsArray *aMessag
       nsCOMPtr<nsIMsgDBHdr> message = do_QueryElementAt(aMessages, i, &rv);
       NS_ENSURE_SUCCESS(rv, rv);
       (void) message->GetMessageKey(&msgKey);
-      if (keywordIsLabel)
-      {
-        nsMsgLabelValue labelValue;
-        message->GetLabel(&labelValue);
-        // if we're removing the keyword that corresponds to a pre 2.0 label,
-        // we need to clear the old label attribute on the messsage.
-        if (labelValue == (nsMsgLabelValue) (aKeyword[6] - '0'))
-          message->SetLabel((nsMsgLabelValue) 0);
-      }
-
       rv = message->GetStringProperty("keywords", getter_Copies(keywords));
-      nsACString::const_iterator start, end;
-      nsACString::const_iterator saveStart;
-      keywords.BeginReading(saveStart);
-      if (MsgFindKeyword(nsDependentCString(aKeyword), keywords, start, end))
+      nsCStringArray keywordArray;
+      keywordArray.ParseString(aKeywords, " ");
+      for (PRInt32 j = 0; j < keywordArray.Count(); j++)
       {
-        keywords.Cut(Distance(saveStart, start), Distance(start, end));
-        mDatabase->SetStringProperty(msgKey, "keywords", keywords);
+        PRBool keywordIsLabel = (StringBeginsWith(*(keywordArray[j]), NS_LITERAL_CSTRING("$label"))  
+          && keywordArray[j]->CharAt(6) >= '1' && keywordArray[j]->CharAt(6) <= '5');
+        if (keywordIsLabel)
+        {
+          nsMsgLabelValue labelValue;
+          message->GetLabel(&labelValue);
+          // if we're removing the keyword that corresponds to a pre 2.0 label,
+          // we need to clear the old label attribute on the messsage.
+          if (labelValue == (nsMsgLabelValue) (keywordArray[j]->CharAt(6) - '0'))
+            message->SetLabel((nsMsgLabelValue) 0);
+        }
+
+        nsACString::const_iterator start, end;
+        nsACString::const_iterator saveStart;
+        keywords.BeginReading(saveStart);
+        if (MsgFindKeyword(*(keywordArray[j]), keywords, start, end))
+        {
+          keywords.Cut(Distance(saveStart, start), Distance(start, end));
+          NS_ASSERTION(keywords.IsEmpty() || keywords.CharAt(0) != ' ', "space only keyword");
+        }
       }
+      mDatabase->SetStringProperty(msgKey, "keywords", keywords);
     }
   }
   return rv;
 }
 
- 
 NS_IMETHODIMP nsMsgDBFolder::GetCustomIdentity(nsIMsgIdentity **aIdentity)
 {
   NS_ENSURE_ARG_POINTER(aIdentity);
diff --git a/mailnews/imap/src/nsImapMailFolder.cpp b/mailnews/imap/src/nsImapMailFolder.cpp
index bccc08b625c..e7b58714554 100644
--- a/mailnews/imap/src/nsImapMailFolder.cpp
+++ b/mailnews/imap/src/nsImapMailFolder.cpp
@@ -3478,7 +3478,7 @@ NS_IMETHODIMP nsImapMailFolder::ApplyFilterHit(nsIMsgFilter *filter, nsIMsgWindo
           nsCOMPtr<nsISupportsArray> messageArray;
           NS_NewISupportsArray(getter_AddRefs(messageArray));
           messageArray->AppendElement(msgHdr);
-          AddKeywordToMessages(messageArray, keyword.get());
+          AddKeywordsToMessages(messageArray, keyword.get());
           break;
         }
         case nsMsgFilterAction::JunkScore:
@@ -8601,32 +8601,32 @@ NS_IMETHODIMP nsImapMailFolder::FetchMsgPreviewText(nsMsgKey *aKeysToFetch, PRUi
   return NS_OK;
 }
 
-NS_IMETHODIMP nsImapMailFolder::AddKeywordToMessages(nsISupportsArray *aMessages, const char *aKeyword)
+NS_IMETHODIMP nsImapMailFolder::AddKeywordsToMessages(nsISupportsArray *aMessages, const char *aKeywords)
 {
-  nsresult rv = nsMsgDBFolder::AddKeywordToMessages(aMessages, aKeyword);
+  nsresult rv = nsMsgDBFolder::AddKeywordsToMessages(aMessages, aKeywords);
   if (NS_SUCCEEDED(rv))
   {
     nsCAutoString messageIds;
     nsMsgKeyArray keys;
     rv = BuildIdsAndKeyArray(aMessages, messageIds, keys);
     NS_ENSURE_SUCCESS(rv, rv);
-    rv = StoreCustomKeywords(nsnull, aKeyword, nsnull, keys.GetArray(), keys.GetSize(), nsnull);
+    rv = StoreCustomKeywords(nsnull, aKeywords, nsnull, keys.GetArray(), keys.GetSize(), nsnull);
     if (mDatabase)
       mDatabase->Commit(nsMsgDBCommitType::kLargeCommit);
   }
   return rv;
 }
 
-NS_IMETHODIMP nsImapMailFolder::RemoveKeywordFromMessages(nsISupportsArray *aMessages, const char *aKeyword)
+NS_IMETHODIMP nsImapMailFolder::RemoveKeywordsFromMessages(nsISupportsArray *aMessages, const char *aKeywords)
 {
-  nsresult rv = nsMsgDBFolder::RemoveKeywordFromMessages(aMessages, aKeyword);
+  nsresult rv = nsMsgDBFolder::RemoveKeywordsFromMessages(aMessages, aKeywords);
   if (NS_SUCCEEDED(rv))
   {
     nsCAutoString messageIds;
     nsMsgKeyArray keys;
     nsresult rv = BuildIdsAndKeyArray(aMessages, messageIds, keys);
     NS_ENSURE_SUCCESS(rv, rv);
-    rv = StoreCustomKeywords(nsnull, nsnull, aKeyword, keys.GetArray(), keys.GetSize(), nsnull);
+    rv = StoreCustomKeywords(nsnull, nsnull, aKeywords, keys.GetArray(), keys.GetSize(), nsnull);
     if (mDatabase)
       mDatabase->Commit(nsMsgDBCommitType::kLargeCommit);
   }
diff --git a/mailnews/imap/src/nsImapMailFolder.h b/mailnews/imap/src/nsImapMailFolder.h
index c6c8e9a9b16..0b10575a390 100644
--- a/mailnews/imap/src/nsImapMailFolder.h
+++ b/mailnews/imap/src/nsImapMailFolder.h
@@ -294,8 +294,8 @@ public:
                                                  PRBool aLocalOnly, nsIUrlListener *aUrlListener, 
                                                  PRBool *aAsyncResults);
 
-  NS_IMETHOD AddKeywordToMessages(nsISupportsArray *aMessages, const char *aKeyword);
-  NS_IMETHOD RemoveKeywordFromMessages(nsISupportsArray *aMessages, const char *aKeyword);
+  NS_IMETHOD AddKeywordsToMessages(nsISupportsArray *aMessages, const char *aKeywords);
+  NS_IMETHOD RemoveKeywordsFromMessages(nsISupportsArray *aMessages, const char *aKeywords);
 
   // nsIMsgImapMailFolder methods
   NS_DECL_NSIMSGIMAPMAILFOLDER
diff --git a/mailnews/local/src/nsLocalMailFolder.cpp b/mailnews/local/src/nsLocalMailFolder.cpp
index 58a51dbf5a8..b1ff0d2ce85 100644
--- a/mailnews/local/src/nsLocalMailFolder.cpp
+++ b/mailnews/local/src/nsLocalMailFolder.cpp
@@ -3921,14 +3921,14 @@ NS_IMETHODIMP nsMsgLocalMailFolder::FetchMsgPreviewText(nsMsgKey *aKeysToFetch,
   return rv;
 }
 
-NS_IMETHODIMP nsMsgLocalMailFolder::AddKeywordToMessages(nsISupportsArray *aMessages, const char *aKeyword)
+NS_IMETHODIMP nsMsgLocalMailFolder::AddKeywordsToMessages(nsISupportsArray *aMessages, const char *aKeywords)
 {
-  return ChangeKeywordForMessages(aMessages, aKeyword, PR_TRUE /* add */);
+  return ChangeKeywordForMessages(aMessages, aKeywords, PR_TRUE /* add */);
 }
-nsresult nsMsgLocalMailFolder::ChangeKeywordForMessages(nsISupportsArray *aMessages, const char *aKeyword, PRBool add)
+nsresult nsMsgLocalMailFolder::ChangeKeywordForMessages(nsISupportsArray *aMessages, const char *aKeywords, PRBool add)
 {
-  nsresult rv = (add) ? nsMsgDBFolder::AddKeywordToMessages(aMessages, aKeyword)
-                      : nsMsgDBFolder::RemoveKeywordFromMessages(aMessages, aKeyword);
+  nsresult rv = (add) ? nsMsgDBFolder::AddKeywordsToMessages(aMessages, aKeywords)
+                      : nsMsgDBFolder::RemoveKeywordsFromMessages(aMessages, aKeywords);
 
   if (NS_SUCCEEDED(rv))
   {
@@ -3945,8 +3945,6 @@ nsresult nsMsgLocalMailFolder::ChangeKeywordForMessages(nsISupportsArray *aMessa
     nsresult rv = aMessages->Count(&count);
     NS_ENSURE_SUCCESS(rv, rv);
     nsXPIDLCString keywords;
-    nsCAutoString keywordToWrite(" ");
-    keywordToWrite.Append(aKeyword);
     // for each message, we seek to the beginning of the x-mozilla-status header, and 
     // start reading lines, looking for x-mozilla-keys: headers; If we're adding
     // the keyword and we find
@@ -3968,85 +3966,94 @@ nsresult nsMsgLocalMailFolder::ChangeKeywordForMessages(nsISupportsArray *aMessa
       nsCOMPtr<nsIMsgDBHdr> message = do_QueryElementAt(aMessages, i, &rv);
       NS_ENSURE_SUCCESS(rv, rv);
       PRUint32 messageOffset;
-      PRUint32 len = 0;
-      nsCAutoString header;
-      nsCAutoString keywords;
       message->GetMessageOffset(&messageOffset);
-      PRBool done = PR_FALSE;
       PRUint32 statusOffset = 0;
       (void)message->GetStatusOffset(&statusOffset);
       PRUint32 desiredOffset = messageOffset + statusOffset;
-      fileStream->seek(PR_SEEK_SET, desiredOffset);
-      PRBool inKeywordHeader = PR_FALSE;
-      PRBool foundKeyword = PR_FALSE;
-      PRUint32 offsetToAddKeyword = 0;
-      message->GetMessageSize(&len);
-      // loop through 
-      while (!done)
-      {
-        lineBuff[0] = '\0';
-        PRInt32 lineStartPos = fileStream->tell();
-        // readLine won't return line termination chars.
-        if (fileStream->readline(lineBuff, sizeof(lineBuff)))
-        {
-          if (EMPTY_MESSAGE_LINE(lineBuff))
-            break; // passed headers; no x-mozilla-keywords header; give up.
-          nsCString keywordHeaders;
-          if (!strncmp(lineBuff, HEADER_X_MOZILLA_KEYWORDS, sizeof(HEADER_X_MOZILLA_KEYWORDS) - 1))
-          {
-            inKeywordHeader = PR_TRUE;
-            keywordHeaders = lineBuff;
-          }
-          else if (inKeywordHeader && (lineBuff[0] == ' ' || lineBuff[0] == '\t'))
-            keywordHeaders = lineBuff;
-          else if (inKeywordHeader)
-            break;
-          else
-            continue;
 
-          PRInt32 keywordHdrLength = keywordHeaders.Length();
-          nsACString::const_iterator start, end;
-          nsACString::const_iterator keywordHdrStart;
-          keywordHeaders.BeginReading(keywordHdrStart);
-          // check if we have the keyword
-          if (MsgFindKeyword(nsDependentCString(aKeyword), keywordHeaders, start, end))
+      nsCStringArray keywordArray;
+      keywordArray.ParseString(aKeywords, " ");
+      for (PRInt32 j = 0; j < keywordArray.Count(); j++)
+      {
+        nsCAutoString header;
+        nsCAutoString keywords;
+        PRBool done = PR_FALSE;
+        PRUint32 len = 0;
+        nsCAutoString keywordToWrite(" ");
+
+        keywordToWrite.Append(*(keywordArray[j]));
+        fileStream->seek(PR_SEEK_SET, desiredOffset);
+        PRBool inKeywordHeader = PR_FALSE;
+        PRBool foundKeyword = PR_FALSE;
+        PRUint32 offsetToAddKeyword = 0;
+        message->GetMessageSize(&len);
+        // loop through 
+        while (!done)
+        {
+          lineBuff[0] = '\0';
+          PRInt32 lineStartPos = fileStream->tell();
+          // readLine won't return line termination chars.
+          if (fileStream->readline(lineBuff, sizeof(lineBuff)))
           {
-            foundKeyword = PR_TRUE;
-            if (!add) // if we're removing, remove it, and break;
+            if (EMPTY_MESSAGE_LINE(lineBuff))
+              break; // passed headers; no x-mozilla-keywords header; give up.
+            nsCString keywordHeaders;
+            if (!strncmp(lineBuff, HEADER_X_MOZILLA_KEYWORDS, sizeof(HEADER_X_MOZILLA_KEYWORDS) - 1))
             {
-              PRInt32 keywordStartOffset = Distance(keywordHdrStart, start);
-              keywordHeaders.Cut(keywordStartOffset, Distance(start, end));
-              for (PRInt32 i = Distance(start, end); i > 0; i--)
-                keywordHeaders.Append(' ');
-              fileStream->seek(PR_SEEK_SET, lineStartPos);
-              fileStream->write(keywordHeaders.get(), keywordHeaders.Length());
+              inKeywordHeader = PR_TRUE;
+              keywordHeaders = lineBuff;
+            }
+            else if (inKeywordHeader && (lineBuff[0] == ' ' || lineBuff[0] == '\t'))
+              keywordHeaders = lineBuff;
+            else if (inKeywordHeader)
+              break;
+            else
+              continue;
+
+            PRInt32 keywordHdrLength = keywordHeaders.Length();
+            nsACString::const_iterator start, end;
+            nsACString::const_iterator keywordHdrStart;
+            keywordHeaders.BeginReading(keywordHdrStart);
+            // check if we have the keyword
+            if (MsgFindKeyword(*(keywordArray[j]), keywordHeaders, start, end))
+            {
+              foundKeyword = PR_TRUE;
+              if (!add) // if we're removing, remove it, and break;
+              {
+                PRInt32 keywordStartOffset = Distance(keywordHdrStart, start);
+                keywordHeaders.Cut(keywordStartOffset, Distance(start, end));
+                for (PRInt32 i = Distance(start, end); i > 0; i--)
+                  keywordHeaders.Append(' ');
+                fileStream->seek(PR_SEEK_SET, lineStartPos);
+                fileStream->write(keywordHeaders.get(), keywordHeaders.Length());
+              }
+              offsetToAddKeyword = 0;
+              // if adding and we already have the keyword, done
+              done = PR_TRUE;
+              break;
+            }
+            // argh, we need to check all the lines to see if we already have the
+            // keyword, but if we don't find it, we want to remember the line and
+            // position where we have room to add the keyword.
+            if (add)
+            {
+              nsCAutoString curKeywordHdr(lineBuff);
+              // strip off line ending spaces.
+              curKeywordHdr.Trim(" ", PR_FALSE, PR_TRUE);
+              if (!offsetToAddKeyword && curKeywordHdr.Length() + keywordToWrite.Length() < keywordHdrLength)
+                offsetToAddKeyword = lineStartPos + curKeywordHdr.Length();
             }
-            offsetToAddKeyword = 0;
-            // if adding and we already have the keyword, done
-            done = PR_TRUE;
-            break;
-          }
-          // argh, we need to check all the lines to see if we already have the
-          // keyword, but if we don't find it, we want to remember the line and
-          // position where we have room to add the keyword.
-          if (add)
-          {
-            nsCAutoString curKeywordHdr(lineBuff);
-            // strip off line ending spaces.
-            curKeywordHdr.Trim(" ", PR_FALSE, PR_TRUE);
-            if (!offsetToAddKeyword && curKeywordHdr.Length() + keywordToWrite.Length() < keywordHdrLength)
-              offsetToAddKeyword = lineStartPos + curKeywordHdr.Length();
           }
         }
-      }
-      if (add && !foundKeyword)
-      {
-        if (!offsetToAddKeyword)
-         message->SetUint32Property("growKeywords", 1);
-        else
+        if (add && !foundKeyword)
         {
-          fileStream->seek(PR_SEEK_SET, offsetToAddKeyword);
-          fileStream->write(keywordToWrite.get(), keywordToWrite.Length());
+          if (!offsetToAddKeyword)
+           message->SetUint32Property("growKeywords", 1);
+          else
+          {
+            fileStream->seek(PR_SEEK_SET, offsetToAddKeyword);
+            fileStream->write(keywordToWrite.get(), keywordToWrite.Length());
+          }
         }
       }
     }
@@ -4055,7 +4062,7 @@ nsresult nsMsgLocalMailFolder::ChangeKeywordForMessages(nsISupportsArray *aMessa
   return rv;
 }
 
-NS_IMETHODIMP nsMsgLocalMailFolder::RemoveKeywordFromMessages(nsISupportsArray *aMessages, const char *aKeyword)
+NS_IMETHODIMP nsMsgLocalMailFolder::RemoveKeywordsFromMessages(nsISupportsArray *aMessages, const char *aKeywords)
 {
-  return ChangeKeywordForMessages(aMessages, aKeyword, PR_FALSE /* remove */);
+  return ChangeKeywordForMessages(aMessages, aKeywords, PR_FALSE /* remove */);
 }
diff --git a/mailnews/local/src/nsLocalMailFolder.h b/mailnews/local/src/nsLocalMailFolder.h
index d7006c54532..2cf77b0a543 100644
--- a/mailnews/local/src/nsLocalMailFolder.h
+++ b/mailnews/local/src/nsLocalMailFolder.h
@@ -197,8 +197,8 @@ public:
   NS_IMETHOD FetchMsgPreviewText(nsMsgKey *aKeysToFetch, PRUint32 aNumKeys,
                                                  PRBool aLocalOnly, nsIUrlListener *aUrlListener, 
                                                  PRBool *aAsyncResults);
-  NS_IMETHOD AddKeywordToMessages(nsISupportsArray *aMessages, const char *aKeyword);
-  NS_IMETHOD RemoveKeywordFromMessages(nsISupportsArray *aMessages, const char *aKeyword);
+  NS_IMETHOD AddKeywordsToMessages(nsISupportsArray *aMessages, const char *aKeywords);
+  NS_IMETHOD RemoveKeywordsFromMessages(nsISupportsArray *aMessages, const char *aKeywords);
 
 protected:
   nsresult CopyFolderAcrossServer(nsIMsgFolder *srcFolder, nsIMsgWindow *msgWindow,nsIMsgCopyServiceListener* listener);
diff --git a/mailnews/local/src/nsParseMailbox.cpp b/mailnews/local/src/nsParseMailbox.cpp
index 452f6ce8dec..d0f992c1ac9 100644
--- a/mailnews/local/src/nsParseMailbox.cpp
+++ b/mailnews/local/src/nsParseMailbox.cpp
@@ -1959,7 +1959,7 @@ NS_IMETHODIMP nsParseNewMailState::ApplyFilterHit(nsIMsgFilter *filter, nsIMsgWi
         nsCOMPtr<nsISupportsArray> messageArray;
         NS_NewISupportsArray(getter_AddRefs(messageArray));
         messageArray->AppendElement(msgHdr);
-        m_downloadFolder->AddKeywordToMessages(messageArray, keyword.get());
+        m_downloadFolder->AddKeywordsToMessages(messageArray, keyword.get());
         break;
       }
       case nsMsgFilterAction::Label:
diff --git a/mailnews/local/src/nsPop3Protocol.cpp b/mailnews/local/src/nsPop3Protocol.cpp
index 87897069cc3..686e62cfe9b 100644
--- a/mailnews/local/src/nsPop3Protocol.cpp
+++ b/mailnews/local/src/nsPop3Protocol.cpp
@@ -402,6 +402,12 @@ net_pop3_write_state(Pop3UidlHost* host, nsIFileSpec *mailDirectory)
   nsFileSpec fileSpec;
   mailDirectory->GetFileSpec(&fileSpec);
   fileSpec += "popstate.dat";
+#ifdef DEBUG_David_Bienvenu
+  PRUint32 fileSize = fileSpec.GetFileSize();
+  // check if popstate.dat is getting emptied out.
+  if (!host || (hash_empty(host->hash) && fileSize > 80))
+    NS_ASSERTION(PR_FALSE, "bad/empty pop3 uidl hash table");
+#endif
   
   nsOutputFileStream outFileStream(fileSpec, PR_WRONLY | PR_CREATE_FILE |
     PR_TRUNCATE);
diff --git a/mailnews/news/src/nsNNTPNewsgroupList.cpp b/mailnews/news/src/nsNNTPNewsgroupList.cpp
index 33cfb063d94..0d141cf242e 100644
--- a/mailnews/news/src/nsNNTPNewsgroupList.cpp
+++ b/mailnews/news/src/nsNNTPNewsgroupList.cpp
@@ -846,7 +846,7 @@ NS_IMETHODIMP nsNNTPNewsgroupList::ApplyFilterHit(nsIMsgFilter *aFilter, nsIMsgW
         messageArray->AppendElement(m_newMsgHdr);
         nsCOMPtr <nsIMsgFolder> folder = do_QueryInterface(m_newsFolder, &rv);
         if (folder)
-          folder->AddKeywordToMessages(messageArray, keyword.get());
+          folder->AddKeywordsToMessages(messageArray, keyword.get());
         break;
       }
       case nsMsgFilterAction::Label: