diff -uNr bin/MailScanner.orig bin/MailScanner
--- bin/MailScanner.orig	2004-03-08 19:29:59.000000000 +0000
+++ bin/MailScanner	2004-03-19 13:37:44.000000000 +0000
@@ -173,6 +173,19 @@
 CheckModuleVersions();
 # Can't do this here, config not read yet: CheckQueuesAreTogether();
 
+# Check if we have a local "custom config file" defined, and if we do,
+# require it, so we can use the functions from it. This saves people
+# attempting to maintain patches specific to their installation against
+# the MailScanner distribution.
+my($lconfig);
+$lconfig = MailScanner::Config::QuickPeek($ConfFile, 'localcustomconfig');
+if($lconfig) {
+  eval { require $lconfig; };
+  if($@) {
+    die("Error loading local config functions from $lconfig: $@\n");
+  }
+}
+
 #
 # Need MaxChildren to know how many children to fork
 #      Debug       to know whether to terminate
diff -uNr etc/MailScanner.conf.orig etc/MailScanner.conf
--- etc/MailScanner.conf.orig	2004-03-08 19:28:57.000000000 +0000
+++ etc/MailScanner.conf	2004-03-19 13:39:15.000000000 +0000
@@ -54,6 +54,12 @@
 # ---------------
 #
 
+# Where do we load the custom rules for config from. This should be
+# a perl file that can be require()d, and all the functions should
+# be in the package LocalConfig. If you don't know what any of the
+# above means, it doesn't apply to you, and you shouldn't worry.
+#Local Custom Config = /usr/local/lib/MailScannerLocalConfig.pm
+
 # How many MailScanner processes do you want to run at a time?
 # There is no point increasing this figure if your MailScanner server
 # is happily keeping up with your mail traffic.
diff -uNr lib/MailScanner/Config.pm.orig lib/MailScanner/Config.pm
--- lib/MailScanner/Config.pm.orig	2004-02-29 19:00:21.000000000 +0000
+++ lib/MailScanner/Config.pm	2004-03-19 13:48:44.000000000 +0000
@@ -84,6 +84,19 @@
 $DefaultAddressRegexp = '^.*\@.*\.?$';
 $DefaultVirusRegexp = '.*';
 
+# Do the search for custom config functions
+sub CustomSearch {
+  my($fn, @search) = @_;
+
+  my($path);
+  foreach $path (@search) {
+    if(defined($path->can($fn))) {
+      return $path . "::" . $fn;
+    }
+  }
+  return undef;
+}
+
 # Need to read in a filename/ruleset whose value is the location of
 # filename.rules.conf files. Check every rule of every ruleset in
 # turn, stopping with the result of the first rule that matches.
@@ -114,7 +127,10 @@
   # User custom-written functions are easy to spot too
   $funcname = $CustomFunctions{$name};
   if ($funcname) {
-    $funcname = 'MailScanner::CustomConfig::' . $funcname;
+    $funcname = CustomSearch($funcname, "LocalConfig", "MailScanner::CustomConfig");
+    if(!defined($funcname)) {
+      MailScanner::Log::DieLog("CustomConfig: can't find function $funcname");
+    }
     no strict 'refs';
     $result = &$funcname($msg);
     use strict 'refs';
@@ -717,7 +733,15 @@
     next unless $custom;
     MailScanner::Log::InfoLog("Config: calling custom init function %s",
                               $custom);
-    $fn = 'MailScanner::CustomConfig::Init' . $custom;
+    $fn = CustomSearch("Init" . $custom, "LocalConfig", "MailScanner::CustomConfig");
+    if(!defined($fn)) { 
+      MailScanner::Log::InfoLog("Config: couldn't find custom init function %s",
+                                $custom);
+      if(!defined(CustomSearch($custom, "LocalConfig", "MailScanner::CustomCofig"))) {
+        MailScanner::Log::DieLog("Config: Main function %s doesn't exist",$custom);
+      }
+      next;
+    }
     no strict 'refs';
     &$fn();
     use strict 'refs';
@@ -742,7 +766,12 @@
     next unless $custom;
     MailScanner::Log::InfoLog("Config: calling custom end function %s",
                               $custom);
-    $fn = 'MailScanner::CustomConfig::End' . $custom;
+    $fn = CustomSearch("End" . $custom, "LocalConfig", "MailScanner::CustomConfig");
+    if(!defined($fn)) { 
+      MailScanner::Log::InfoLog("Config: couldn't find custom end function %s",
+                                $custom);
+      next;
+    }
     no strict 'refs';
     &$fn();
     use strict 'refs';
diff -uNr lib/MailScanner/ConfigDefs.pl.orig lib/MailScanner/ConfigDefs.pl
--- lib/MailScanner/ConfigDefs.pl.orig	2004-03-02 11:40:53.000000000 +0000
+++ lib/MailScanner/ConfigDefs.pl	2004-03-19 15:52:26.000000000 +0000
@@ -202,6 +202,7 @@
 SpamListDefinitions	/opt/MailScanner/etc/spam.lists.conf
 mcpspamassassinprefsfile /opt/MailScanner/etc/mcp/mcp.spam.assassin.prefs.conf
 VirusScannerDefinitions	/opt/MailScanner/etc/virus.scanners.conf
+LocalCustomConfig
 
 # Check these to ensure they are just numbers
 [Simple,Number]