Hi, I'm trying to integrate a paypal ipn and I got the Following error while PayPal is Calling my script here is the code

#!/usr/bin/perl

use strict;
use MyDB;
use warnings;
use Email::Sender::Simple qw(sendmail);
use Email::Sender::Transport::SMTPS ();
use Email::Simple ();
use Email::Simple::Creator ();

my $smtpserver = 'smtp.gmail.com';
my $smtpport = '587';
my $smtpuser   = 'xxxxx@gmail.com';
my $smtppassword = 'yyyyyyyccccc';

my $transport = Email::Sender::Transport::SMTPS->new({
  host => $smtpserver,
  port => $smtpport,
  ssl => "starttls",
  sasl_username => $smtpuser,
  sasl_password => $smtppassword,
});
#my $Just_Exit = 0; # if you need it

# Lots of servers will not resolve the IP to a host name
# So variable $ENV{'REMOTE_HOST'} will not have a value.
# If you want any security check if it is a PayPal IP.
#die('Does not match PayPal at IP:'.$ENV{'REMOTE_ADDR'})
# if ($ENV{'REMOTE_ADDR'} ne '173.0.82.66');

# comment the one your not using
my $PP_server = 'ipnpb.sandbox.paypal.com'; # sandbox IP:173.0.82.66
#my $PP_server = 'ipnpb.paypal.com'; # production IP:173.0.88.40

# It is highly recommended that you use version 6 upwards of
# the UserAgent module since it provides for tighter server
# certificate validation
use LWP::UserAgent 6;

# read post from PayPal system and add 'cmd'
use CGI qw(:standard);
my $cgi = CGI->new();
my $db = MyDB->new();
my $query = 'cmd=_notify-validate&';
$query .= join('&', map { $_.'='.$cgi->param($_) } $cgi->param());

# post back to PayPal system to validate
my $ua = LWP::UserAgent->new(ssl_opts => { keep_alive => 1, verify_hos
+tname => 1,SSL_version => 'SSLv23:!TLSv12' });
my $req = HTTP::Request->new('POST', 'https://'.$PP_server.'/cgi-bin/w
+ebscr');
$req->content_type('application/x-www-form-urlencoded');
$req->header(Host => $PP_server);
$req->content($query);
my $res = $ua->request($req);

# make the variable hash
my %variable =
 map { split(m'='x, $_, 2) }
 grep { m'='x }
 split(m'&'x, $query);

# assign posted variables to local variables
my $item_name = $variable{'item_name'};
my $item_number = $variable{'item_number'};
my $payment_status = $variable{'payment_status'};
my $payment_amount = $variable{'mc_gross'};
my $payment_currency = $variable{'mc_currency'};
my $txn_id = $variable{'txn_id'};
my $receiver_email = $variable{'receiver_email'};
my $payer_email = $variable{'payer_email'};

if ($res->is_error) {
 # HTTP error
}
elsif ($res->content eq 'VERIFIED') {
 # check the $variable{'payment_status'}=Completed
 if ($payment_status eq 'Completed') {
   my  ($tx)=$db->sqlSelect("tx", "article", "id_article = $item_numbe
+r");                
   if (!$tx eq $txn_id) {                          
    if ($receiver_email eq 'alexjaquet@gmmail.com') {
     print "Success";
     my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst)=localtim
+e();
     my  $date = sprintf "%4d-%02d-%02d",$year+1900,$mon+3,$mday;    
     my  $time = sprintf("%4d:%02d:%02d",$hour,$min,$sec);            
+  
     $db->sqlUpdate("article","id_article = $item_number",(
                     tx  => "$txn_id",
                     pub => "1".
                     pub_date_end  => "$date $time$item_number"
                    ));
    my $email = Email::Simple->create(
               header => [
                     To      => 'alexjaquet@gmail.com',
                     From    => 'robot@avant-garde.info',
                     Subject => 'Vous avez reçu le payement',
                ],
               body => 'Vous avez reçu le payement',);             
               sendmail($email, { transport => $transport });      
             }
        }        
  }
}
elsif ($res->content eq 'INVALID') {
 # log for manual investigation
        print "Content-Type: text/html\n\n"; 
        print "Erreur dans le payemeent d\'une publicité";
        my $email = Email::Simple->create(
                    header => [
                    To      => 'alexjaquet@gmail.com',
                    From    => 'robot@avant-garde.info',
                    Subject => 'Erreur dans le payement' ],
                    body => 'Erreur dans le payement d\'une publicite 
+: $id_article',);
       sendmail($email, { transport => $transport });              
}
else {
 # error
# log for manual investigation
        print "Content-Type: text/html\n\n"; 
        print "Erreur dans le payemeenté";}
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The log file show me Tue Nov 26 17:31:58.528979 2019 cgi:error pid 2202 client 173.0.82.126:36191 End of script output before headers: ipn.pl Hope you can help