sub hook_helo
{
    my ( $self, $transaction, $host ) = @_;

    #
    #  Make sure helo includes a domain
    #
    if ( $host !~ /\./ )
    {
        $self->log( LOGWARN, "HELO $host doesn't contain a period." );
        $transaction->notes( "reject", 1 );
        $transaction->notes( "reason", "invalid helo" );
    }

    return DECLINED;
}