diff -r 2fdc9cc89502 -r bb6990c0dd1a org/sonews/mlgw/Dispatcher.java
--- a/org/sonews/mlgw/Dispatcher.java	Wed Jul 22 14:04:05 2009 +0200
+++ b/org/sonews/mlgw/Dispatcher.java	Thu Aug 20 14:31:19 2009 +0200
@@ -21,6 +21,8 @@
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 import javax.mail.Address;
 import javax.mail.Authenticator;
 import javax.mail.Message;
@@ -29,6 +31,7 @@
 import javax.mail.internet.InternetAddress;
 import org.sonews.config.Config;
 import org.sonews.storage.Article;
+import org.sonews.storage.Group;
 import org.sonews.storage.Headers;
 import org.sonews.storage.StorageBackendException;
 import org.sonews.storage.StorageManager;
@@ -36,7 +39,7 @@
 import org.sonews.util.Stats;
 
 /**
- * Dispatches messages from mailing list or newsserver or vice versa.
+ * Dispatches messages from mailing list to newsserver or vice versa.
  * @author Christian Lins
  * @since sonews/0.5.0
  */
@@ -58,86 +61,160 @@
     }
     
   }
+
+  /**
+   * Chunks out the email address of the full List-Post header field.
+   * @param listPostValue
+   * @return The matching email address or null
+   */
+  private static String chunkListPost(String listPostValue)
+  {
+    // listPostValue is of form "<mailto:dev@openoffice.org>"
+    Pattern mailPattern = Pattern.compile("(\\w+[-|.])*\\w+@(\\w+.)+\\w+");
+    Matcher mailMatcher = mailPattern.matcher(listPostValue);
+    if(mailMatcher.find())
+    {
+      return listPostValue.substring(mailMatcher.start(), mailMatcher.end());
+    }
+    else
+    {
+      return null;
+    }
+  }
+
+  /**
+   * This method inspects the header of the given message, trying
+   * to find the most appropriate recipient.
+   * @param msg
+   * @param fallback If this is false only List-Post and X-List-Post headers
+   *                 are examined.
+   * @return null or fitting group name for the given message.
+   */
+  private static List<String> getGroupFor(final Message msg, final boolean fallback)
+    throws MessagingException, StorageBackendException
+  {
+    List<String> groups = null;
+
+    // Is there a List-Post header?
+    String[]        listPost = msg.getHeader(Headers.LIST_POST);
+    InternetAddress listPostAddr;
+
+    if(listPost == null || listPost.length == 0 || "".equals(listPost[0]))
+    {
+      // Is there a X-List-Post header?
+      listPost = msg.getHeader(Headers.X_LIST_POST);
+    }
+
+    if(listPost != null && listPost.length > 0 
+      && !"".equals(listPost[0]) && chunkListPost(listPost[0]) != null)
+    {
+      // listPost[0] is of form "<mailto:dev@openoffice.org>"
+      listPost[0]  = chunkListPost(listPost[0]);
+      listPostAddr = new InternetAddress(listPost[0], false);
+      groups = StorageManager.current().getGroupsForList(listPostAddr);
+    }
+    else if(fallback)
+    {
+      Log.msg("Using fallback recipient discovery for: " + msg.getSubject(), true);
+      groups = new ArrayList<String>();
+      // Fallback to TO/CC/BCC addresses
+      Address[] to = msg.getAllRecipients();
+      for(Address toa : to) // Address can have '<' '>' around
+      {
+        if(toa instanceof InternetAddress)
+        {
+          List<String> g = StorageManager.current().getGroupsForList((InternetAddress) toa);
+          groups.addAll(g);
+        }
+      }
+    }
+    
+    return groups;
+  }
   
   /**
    * Posts a message that was received from a mailing list to the 
    * appropriate newsgroup.
+   * If the message already exists in the storage, this message checks
+   * if it must be posted in an additional group. This can happen for
+   * crosspostings in different mailing lists.
    * @param msg
    */
   public static boolean toGroup(final Message msg)
   {
     try
     {
-      Address[] to = msg.getAllRecipients(); // includes TO/CC/BCC
-      if(to == null || to.length <= 0)
+      // Create new Article object
+      Article article = new Article(msg);
+      boolean posted  = false;
+
+      // Check if this mail is already existing the storage
+      boolean updateReq = 
+        StorageManager.current().isArticleExisting(article.getMessageID());
+
+      List<String> newsgroups = getGroupFor(msg, !updateReq);
+      List<String> oldgroups  = new ArrayList<String>();
+      if(updateReq)
       {
-        to = msg.getReplyTo();
+        // Check for duplicate entries of the same group
+        Article oldArticle = StorageManager.current().getArticle(article.getMessageID());
+        List<Group> oldGroups = oldArticle.getGroups();
+        for(Group oldGroup : oldGroups)
+        {
+          if(!newsgroups.contains(oldGroup.getName()))
+          {
+            oldgroups.add(oldGroup.getName());
+          }
+        }
       }
 
-      if(to == null || to.length <= 0)
+      if(newsgroups.size() > 0)
       {
-        Log.msg("Skipping message because no recipient!", false);
-        return false;
+        newsgroups.addAll(oldgroups);
+        StringBuilder groups = new StringBuilder();
+        for(int n = 0; n < newsgroups.size(); n++)
+        {
+          groups.append(newsgroups.get(n));
+          if (n + 1 != newsgroups.size())
+          {
+            groups.append(',');
+          }
+        }
+        Log.msg("Posting to group " + groups.toString(), true);
+
+        article.setGroup(groups.toString());
+        //article.removeHeader(Headers.REPLY_TO);
+        //article.removeHeader(Headers.TO);
+
+        // Write article to database
+        if(updateReq)
+        {
+          Log.msg("Updating " + article.getMessageID() + " with additional groups", true);
+          StorageManager.current().delete(article.getMessageID());
+          StorageManager.current().addArticle(article);
+        }
+        else
+        {
+          Log.msg("Gatewaying " + article.getMessageID() + " to "
+            + article.getHeader(Headers.NEWSGROUPS)[0], true);
+          StorageManager.current().addArticle(article);
+          Stats.getInstance().mailGatewayed(
+            article.getHeader(Headers.NEWSGROUPS)[0]);
+        }
+        posted = true;
       }
       else
       {
-        boolean      posted     = false;
-        List<String> newsgroups = new ArrayList<String>();
-
-        for (Address toa : to) // Address can have '<' '>' around
+        StringBuilder buf = new StringBuilder();
+        for (Address toa : msg.getAllRecipients())
         {
-          if (toa instanceof InternetAddress)
-          {
-            List<String> groups = StorageManager.current()
-              .getGroupsForList((InternetAddress)toa);
-            newsgroups.addAll(groups);
-          }
+          buf.append(' ');
+          buf.append(toa.toString());
         }
-
-        if (newsgroups.size() > 0)
-        {
-          StringBuilder groups = new StringBuilder();
-          for(int n = 0; n < newsgroups.size(); n++)
-          {
-            groups.append(newsgroups.get(n));
-            if(n + 1 != newsgroups.size())
-            {
-              groups.append(',');
-            }
-          }
-          Log.msg("Posting to group " + groups.toString(), true);
-
-          // Create new Article object
-          Article article = new Article(msg);
-          article.setGroup(groups.toString());
-          article.removeHeader(Headers.REPLY_TO);
-          article.removeHeader(Headers.TO);
-
-          // Write article to database
-          if(!StorageManager.current().isArticleExisting(article.getMessageID()))
-          {
-            StorageManager.current().addArticle(article);
-            Stats.getInstance().mailGatewayed(
-              article.getHeader(Headers.NEWSGROUPS)[0]);
-          }
-          else
-          {
-            Log.msg("Article " + article.getMessageID() + " already existing.", true);
-          }
-          posted = true;
-        }
-        else
-        {
-          StringBuilder buf = new StringBuilder();
-          for(Address toa : to)
-          {
-            buf.append(' ');
-            buf.append(toa.toString());
-          }
-          Log.msg("No group for" + buf.toString(), false);
-        }
-        return posted;
+        buf.append(" " + article.getHeader(Headers.LIST_POST)[0]);
+        Log.msg("No group for" + buf.toString(), false);
       }
+      return posted;
     }
     catch(Exception ex)
     {
@@ -148,56 +225,53 @@
   
   /**
    * Mails a message received through NNTP to the appropriate mailing list.
+   * This method MAY be called several times by PostCommand for the same
+   * article.
    */
-  public static void toList(Article article)
+  public static void toList(Article article, String group)
     throws IOException, MessagingException, StorageBackendException
   {
     // Get mailing lists for the group of this article
-    List<String> listAddresses = new ArrayList<String>();
-    String[]     groupnames    = article.getHeader(Headers.NEWSGROUPS)[0].split(",");
-    
-    for(String groupname : groupnames)
+    List<String> rcptAddresses = StorageManager.current().getListsForGroup(group);
+
+    if(rcptAddresses == null || rcptAddresses.size() == 0)
     {
-      String listAddress = StorageManager.current().getListForGroup(groupname);
-      if(listAddress != null)
-      {
-        listAddresses.add(listAddress);
-      }
+      Log.msg("No ML-address for " + group + " found.", false);
+      return;
     }
 
-    for(String listAddress : listAddresses)
+    for(String rcptAddress : rcptAddresses)
     {
       // Compose message and send it via given SMTP-Host
       String smtpHost = Config.inst().get(Config.MLSEND_HOST, "localhost");
-      int    smtpPort = Config.inst().get(Config.MLSEND_PORT, 25);
+      int smtpPort = Config.inst().get(Config.MLSEND_PORT, 25);
       String smtpUser = Config.inst().get(Config.MLSEND_USER, "user");
-      String smtpPw   = Config.inst().get(Config.MLSEND_PASSWORD, "mysecret");
+      String smtpPw = Config.inst().get(Config.MLSEND_PASSWORD, "mysecret");
       String smtpFrom = Config.inst().get(
-          Config.MLSEND_ADDRESS, article.getHeader(Headers.FROM)[0]);
+        Config.MLSEND_ADDRESS, article.getHeader(Headers.FROM)[0]);
 
       // TODO: Make Article cloneable()
-      String group = article.getHeader(Headers.NEWSGROUPS)[0];
       article.getMessageID(); // Make sure an ID is existing
       article.removeHeader(Headers.NEWSGROUPS);
       article.removeHeader(Headers.PATH);
       article.removeHeader(Headers.LINES);
       article.removeHeader(Headers.BYTES);
 
-      article.setHeader("To", listAddress);
-      article.setHeader("Reply-To", listAddress);
+      article.setHeader("To", rcptAddress);
+      //article.setHeader("Reply-To", listAddress);
 
-      if(Config.inst().get(Config.MLSEND_RW_SENDER, false))
+      if (Config.inst().get(Config.MLSEND_RW_SENDER, false))
       {
         rewriteSenderAddress(article); // Set the SENDER address
       }
 
       SMTPTransport smtpTransport = new SMTPTransport(smtpHost, smtpPort);
-      smtpTransport.send(article, smtpFrom, listAddress);
+      smtpTransport.send(article, smtpFrom, rcptAddress);
       smtpTransport.close();
 
       Stats.getInstance().mailGatewayed(group);
-      Log.msg("MLGateway: Mail " + article.getHeader("Subject")[0] 
-        + " was delivered to " + listAddress + ".", true);
+      Log.msg("MLGateway: Mail " + article.getHeader("Subject")[0]
+        + " was delivered to " + rcptAddress + ".", true);
     }
   }