sendmail のパスはサーバによって違うが、
大体したのような感じ

sub sendmail{
my ($title,$from,$to,$contents) = @_;
my $mail_title = "";

$mail_title = $title;
$mail_title = &jcode::sjis($mail_title);
while ($mail_title =~ /\n$/){
$mail_title =~ s/\n$//g;
}
$mail_title = &jcode::jis($mail_title);

open(MAIL,"|/usr/lib/sendmail $to");
print MAIL "Content-Type: text/plain; charset=ISO-2022-JP\n";
print MAIL "Content-Transfer-Encoding: 7bit\n";
print MAIL 'Subject: '.$mail_title." \n";
print MAIL "From: $from\n";
print MAIL "To: $to\n\n";
print MAIL "$contents\n";
close(MAIL);
}