my $sendmail = "/usr/sbin/sendmail -t";
my $reply_to = "Reply-to: foo\@bar.com\n";
my $subject  = "Subject: Confirmation of your submission\n";
my $content  = "Thanks for your submission.";
my $to       = "bar\@foo.com\n";
my $send_to  = "To: ". $to;

open(SENDMAIL, "|$sendmail") or die "Cannot open $sendmail: $!";
print SENDMAIL $reply_to;
print SENDMAIL $subject;
print SENDMAIL $send_to;
print SENDMAIL "Content-type: text/plain\n\n";
print SENDMAIL $content;
close(SENDMAIL);