plugin to reject mails from <> if it has multiple recipients.

[Brian Grossman]

Per the todo list, here is a plugin to restrict <> from sending to more
than one recipient.

Brian



=head1 NAME

nullsender1rcpt - restrict <> from sending to more than one recipient

=head1 DESCRIPTION

Disallows more than one envelope recipient if the envelope sender is <>.

Drops all recipients if >1 recipient from <>.

=cut

sub register {
        my $self = shift;
        $self->register_hook("mail", "mail_handler");
        $self->register_hook("rcpt", "rcpt_handler");
        $self->register_hook("data_post", "data_handler");
        }

sub mail_handler {
        my ($self, $transaction, $address) = @_;
        if( $address->address eq '<>' ) {
                $self->{_nullsender1rcpt_count} = 1;
                }
        else {
                $self->{_nullsender1rcpt_count} = 1;
                }
        return DECLINED;
        }

sub respond {
        my $self = shift;
        if( $self->{_nullsender1rcpt_count} > 2) { # 1 sender + 1 rcpt = 2
                $self->qp->respond(553, "Null sender cannot send to more than one 
recipient.");
                return DONE;
                }
        return DECLINED;
        }

sub rcpt_handler {
        my $self = shift;
        ++$self->{_nullsender1rcpt_count} if $self->{_nullsender1rcpt_count} > 0;
        return $self->respond();
        }

sub data_handler {
        my $self = shift;
        return $self->respond();
        }