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function send_pdf( $cf7 ) {
	if (is_single("property")){
		$id = $cf7->id();
		$pdf_path = wp_get_attachment_url( $property->field( 'property_pdf_documentation.ID' ));
		
		if ($id==109){
			$submission = WPCF7_Submission::get_instance();
			$submission->add_uploaded_file('pdf', $pdf_path);
		}
	}
}

add_action('wpcf7_before_send_mail','send_pdf');