diff --git a/sbin/newsletter-transport.pl b/sbin/newsletter-transport.pl
index d26eaf8..8b59b0a 100755
--- a/sbin/newsletter-transport.pl
+++ b/sbin/newsletter-transport.pl
@@ -9,17 +9,20 @@ BEGIN {
 
 use strict;
 use warnings;
+use 5.010;
 
-#use Mail::DeliveryStatus::BounceParser;
-#use WebGUI::Mailing::Email;
 use WebGUI::MailCommand;
 use List::MoreUtils qw{ any };
 use WebGUI::Config;
 use Getopt::Long;
+use Readonly;
 
-use 5.010;
+Readonly my $WRONG_USAGE    => 64; 
+Readonly my $DATA_ERROR     => 65; 
+Readonly my $NO_SUCH_USER   => 67; 
+Readonly my $UNKNOWN_HOST   => 68;
+Readonly my $CONFIG_ERROR   => 78;
 
-my $NO_SUCH_USER    = 67;
 my $webguiRoot      = '/data/WebGUI';
 
 #---------------------------------------------------------------
@@ -41,7 +44,9 @@ my $webguiRoot      = '/data/WebGUI';
         closeSession( $session );
     }
     else {
-        die "Not a valid command [$command].";
+        warn "Not a valid command [$command]."; 
+        exit( $NO_SUCH_USER );
+        #die "Not a valid command [$command].";
     }
 
     exit(0);
@@ -57,22 +62,22 @@ sub getCredentials {
         'sender=s'  => \$sender,
         'senderIp=s'=> \$senderIp,
     );
-    die "--domain parameter is required" unless $domain;
-    die "--user parameter is required" unless $user;
-    die "--sender parameter is required" unless $sender;
-    die "--senderIp parameter is required" unless $senderIp;
+    warn "--domain parameter is required"   && exit( $WRONG_USAGE ) unless $domain;
+    warn "--user parameter is required"     && exit( $WRONG_USAGE ) unless $user;
+    warn "--sender parameter is required"   && exit( $WRONG_USAGE ) unless $sender;
+    warn "--senderIp parameter is required" && exit( $WRONG_USAGE ) unless $senderIp;
 
     my $dispatch = WebGUI::Config->new( $webguiRoot, 'mailing_dispatch.config' )
-        || die "Cannot open $webguiRoot/etc/mailing_dispatch.config";
+        ||  warn "Cannot open $webguiRoot/etc/mailing_dispatch.config" && exit( $CONFIG_ERROR );
 
     my $configFile = $dispatch->get( $domain )
-        || die "Received mail for domain [$domain] which is not configured!";
+        ||  warn "Received mail for domain [$domain] which is not configured!" && exit( $UNKNOWN_HOST );
 
     # Format is mailId-command
     my ( $id, $command ) = $user =~ m{ ^ (.+) - ([^-]+) $ }ix;
 
-    die "Received mail addressed to [$user\@$domain] which contains no id"      unless $id;
-    die "Received mail addressed to [$user\@$domain] which contains no command" unless $command;
+    print "Received mail addressed to [$user\@$domain] which contains no id"      && exit( $NO_SUCH_USER ) unless $id;
+    print "Received mail addressed to [$user\@$domain] which contains no command" && exit( $NO_SUCH_USER ) unless $command;
 
 
     return ( $configFile, $command, $id, $sender, $senderIp );