# UNTESTED
my $sendmail_bin = '/bin/sendmail'; # maybe use File::Which::which(), might not work on a cgi for example
open(OUT, "|$sendmail_bin -t") or die("cant open pipe to sendmail [$sendmail_bin]");
my ($from, $recipient, $subject, $reply)= 
  qw(me@this.net user@destination.ext bogus no@reply.net);

# print header and content
print OUT <<EOM
From : $from
To: $recipient
Subject: $subject
Reply-To: $reply
[This message is junk.]

Hi hi.. whatzzzzzuuuupppp... 
EOM
;
close(OUT);