if (defined(my $pid=fork())) {
    if ($pid) {
    # $pid is not 0, so this is the parent
    # Let's redirect the user.
    print header,
          start_html,
          h2('Sending Mail...'),
          "\t<meta http-equiv=\"refresh\" content=\"5; url=http://host.mydomain.com\">\n",
          end_html;
          $SIG{CHLD}='IGNORE';
          exit;
    }else{
        # $pid=0, so this is the child
        $retval=build_mail();
        exit $retval;
    }
}else{
    # Oops, fork() returned undef - something is definitely wrong.
    DieNice("Unable to fork: $!\n");
}

# Do your time consuming stuff, setting $retval to
# a useful number
sub build_mail {
    
    while (<@to>){
        chomp($_);
        push @chunk, $_;
        $count ++; 
        if ($count == 80){ #splits bcc into small chuncks
            $to = join ",", @chunk;
            mailout();
            $count = 0;
            @chunk = ();
        }
    }
    
    $to = join ",", @chunk;
    mailout();
    
    return $retval;
}