--- vacation.pl.original	2009-03-15 16:42:57.000000000 -0600
+++ vacation.pl	2009-03-26 18:29:48.000000000 -0600
@@ -40,6 +40,9 @@
 #             Properly handle failed queries to vacation_notification.
 #             Fixed log reporting.
 #
+# 2009-01-10  Gary V - mr88talent at yahoo dot com
+#             Patched to allow the use of sendmail binary instead of Mail::Sendmail
+#
 # Requirements:
 # You need to have the DBD::Pg or DBD::mysql perl-module installed.
 # You need to have the Mail::Sendmail module installed. 
@@ -87,7 +90,11 @@
 my $db_name     = 'postfix';
 
 # smtp server used to send vacation e-mails
+# You can use smtp ($use_smtp = 1;) which uses Mail::Sendmail
+# or instead use the sendmail binary ($use_smtp = 0;)
 my $smtp_server = 'localhost';
+my $sendmail = "/usr/sbin/sendmail";
+my $use_smtp = 0;
 
 my $syslog = 1;
 
@@ -164,7 +171,7 @@
 
 # Violation of a primay key constraint may happen here, and that's
 # fine. All other error conditions are not fine, however.
-      if ($e !~ /_pkey/) {
+      if ($e !~ /(?:_pkey|^Duplicate entry)/) {
          do_log('',$to,$from,'',"Unexpected error: '$e' from query '$query'");
 
          # Let's play safe and notify anyway
@@ -222,6 +229,21 @@
    do_debug('Mail::Sendmail said :' . $Mail::Sendmail::log);
 }
 
+sub do_mail_sendmail {
+   my ($from, $to, $subject, $body, $orig_msgID) = @_;
+   open (MAIL, "| $sendmail -t -f  \"<>\"") or die ("Unable to open sendmail");
+   print MAIL "From: $from\n";
+   print MAIL "To: $to\n";
+   print MAIL "Subject: $subject\n";
+   if ( $orig_msgID ) {
+        print MAIL "References: $orig_msgID\n";
+        print MAIL "In-Reply-To: $orig_msgID\n";
+   }
+   print MAIL "X-Loop: Postfix Admin Virtual Vacation\n\n";
+   print MAIL "$body";
+   close (MAIL) or die ("Unable to close sendmail");
+}
+
 sub panic {
    my ($arg) = @_;
    do_log('','','','',"$arg");
@@ -313,8 +335,12 @@
       if (already_notified($email, $orig_from)) { return; }
       do_debug ("[SEND RESPONSE] for $orig_messageid:\n", "FROM: $email (orig_to: $orig_to)\n", "TO: $orig_from\n", "VACATION SUBJECT: $row[0]\n", "VACATION BODY: $row[1]\n");
 
-      # do_mail(from, to, subject, body);
-      do_mail ($email, $orig_from, $row[0], $row[1]);
+      # do_mail(from, to, subject, body); or do_mail_sendmail(from, to, subject, body, original message ID); 
+      if ($use_smtp) {
+        do_mail ($email, $orig_from, $row[0], $row[1]);
+      } else { 
+        do_mail_sendmail ($email, $orig_from, $row[0], $row[1], $orig_messageid);
+      }
       do_log ($orig_messageid, $orig_to, $orig_from, ''); 
    }