From af03c53512e3e174bbba60f5171e0582b8bd2a3b Mon Sep 17 00:00:00 2001
From: John Peacock <jpeacock@cpan.org>
Date: Wed, 13 Oct 2004 01:52:35 +0000
Subject: [PATCH] plugins/spamassassin     New option to strip/rename/keep old
 X-Spam headers (Michael Holzt)

git-svn-id: https://svn.perl.org/qpsmtpd/trunk@335 958fd67b-6ff1-0310-b445-bb7760255be9
---
 plugins/spamassassin | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/plugins/spamassassin b/plugins/spamassassin
index 02a89ef..be8c660 100644
--- a/plugins/spamassassin
+++ b/plugins/spamassassin
@@ -50,6 +50,14 @@ Beginning with Mail::SpamAssassin 2.60, it is possible to use Unix
 domain sockets for spamd.  This is faster and more secure than using
 a TCP connection.
 
+=item leave_old_headers [drop|rename|keep]
+
+Another mail server before might have checked this mail already and may have
+added X-Spam-Status, X-Spam-Flag and X-Spam-Check-By lines. Normally you can
+not trust such headers and should either rename them to X-Old-... (default,
+parameter 'rename') or have them removed (parameter 'drop'). If you know
+what you are doing, you can also leave them intact (parameter 'keep').
+
 =back
 
 With both of the first options the configuration line will look like the following
@@ -89,6 +97,8 @@ sub check_spam {
   $self->log(6, "check_spam");
   return (DECLINED) if $transaction->body_size > 500_000;
 
+  my $leave_old_headers = lc($self->{_args}->{leave_old_headers}) || 'rename';
+
   my $remote  = 'localhost';
   my $port    = 783;
   if ($port =~ /\D/) { $port = getservbyname($port, 'tcp') }
@@ -144,6 +154,20 @@ sub check_spam {
   my $line0 = <SPAMD>; # get the first protocol lines out
   if ($line0) {
     $self->log(6, "check_spam: spamd: $line0");
+
+    if ( $leave_old_headers eq 'rename' )
+    {
+      foreach my $header ( $transaction->header->get('X-Spam-Check-By') )
+      {
+        $transaction->header->add('X-Old-Spam-Check-By', $header);
+      }
+    }
+    
+    if ( $leave_old_headers eq 'drop' || $leave_old_headers eq 'rename' )
+    {
+      $transaction->header->delete('X-Spam-Check-By');
+    }
+
     $transaction->header->add("X-Spam-Check-By", $self->qp->config('me'), 0);
   }
 
@@ -162,6 +186,25 @@ sub check_spam {
   $flag = $flag eq 'True' ? 'Yes' : 'No';
   $self->log(6, "check_spam: finished reading from spamd");
 
+  if ( $leave_old_headers eq 'rename' )
+  {
+    foreach my $header ( $transaction->header->get('X-Spam-Flag') )
+    {
+      $transaction->header->add('X-Old-Spam-Flag', $header);
+    }
+
+    foreach my $header ( $transaction->header->get('X-Spam-Status') )
+    {
+      $transaction->header->add('X-Old-Spam-Status', $header);
+    }
+  }
+    
+  if ( $leave_old_headers eq 'drop' || $leave_old_headers eq 'rename' )
+  {
+    $transaction->header->delete('X-Spam-Flag');
+    $transaction->header->delete('X-Spam-Status');
+  }
+
   $transaction->header->add('X-Spam-Flag', 'YES', 0) if ($flag eq 'Yes');
   $transaction->header->add('X-Spam-Status',
 			    "$flag, hits=$hits required=$required\n" .