<modification>
        <id>OCA_Detailed Order Admin Email Notification(1.5.x)</id>
        <version>1.0</version>
        <vqmver>1.0.0</vqmver>
        <author>Joel - http://opencartaddons.com - [email protected]</author>
        <file name="catalog/model/checkout/order.php">
				<operation>
						<search position="replace"><![CDATA[$mail->setText($text);]]></search>
                        <add><![CDATA[
						$mail->setHtml($html);
						$mail->setText(html_entity_decode($text, ENT_QUOTES, 'UTF-8'));
						$mail->addAttachment(DIR_IMAGE . $this->config->get('config_logo'));
						]]></add>
				</operation>
				<operation>
						<search position="before" index="2"><![CDATA[$mail = new Mail();]]></search>
                        <add><![CDATA[
						// HTML Mail
						$template = new Template();
						
						$template->data['title'] = sprintf($language->get('text_new_subject'), html_entity_decode($order_info['store_name'], ENT_QUOTES, 'UTF-8'), $order_id);
						
						$template->data['text_greeting'] = sprintf($language->get('text_new_received'));
						$template->data['text_link'] = '';
						$template->data['text_download'] = '';
						$template->data['text_order_detail'] = $language->get('text_new_order_detail');
						$template->data['text_invoice_no'] = $language->get('text_new_invoice_no');
						$template->data['text_order_id'] = $language->get('text_new_order_id');
						$template->data['text_date_added'] = $language->get('text_new_date_added');
						$template->data['text_payment_method'] = $language->get('text_new_payment_method');	
						$template->data['text_shipping_method'] = $language->get('text_new_shipping_method');
						$template->data['text_email'] = $language->get('text_new_email');
						$template->data['text_telephone'] = $language->get('text_new_telephone');
						$template->data['text_ip'] = $language->get('text_new_ip');
						$template->data['text_payment_address'] = $language->get('text_new_payment_address');
						$template->data['text_shipping_address'] = $language->get('text_new_shipping_address');
						$template->data['text_product'] = $language->get('text_new_product');
						$template->data['text_model'] = $language->get('text_new_model');
						$template->data['text_quantity'] = $language->get('text_new_quantity');
						$template->data['text_price'] = $language->get('text_new_price');
						$template->data['text_total'] = $language->get('text_new_total');
						$template->data['text_footer'] = '';
						$template->data['text_powered'] = '';
						
						$template->data['logo'] = 'cid:' . basename($this->config->get('config_logo'));		
						$template->data['store_name'] = $order_info['store_name'];
						$template->data['store_url'] = $order_info['store_url'];
						$template->data['customer_id'] = $order_info['customer_id'];
						$template->data['link'] = '';
						$template->data['download'] = '';
						
						if (isset($comment) && isset($notify)) {
							if ($comment && $notify) {
								$template->data['comment'] = nl2br($comment);
							} else {
								$template->data['comment'] = '';
							}
						}
						
						$template->data['invoice_no'] = $invoice_no;
						$template->data['order_id'] = $order_id;
						$template->data['date_added'] = date($language->get('date_format_short'), strtotime($order_info['date_added']));    	
						$template->data['payment_method'] = $order_info['payment_method'];
						$template->data['shipping_method'] = $order_info['shipping_method'];
						$template->data['email'] = $order_info['email'];
						$template->data['telephone'] = $order_info['telephone'];
						$template->data['ip'] = $order_info['ip'] . '<br/><b>' . $language->get('text_new_order_status') . '</b> ' . $order_status;
												
						if ($order_info['shipping_address_format']) {
							$format = $order_info['shipping_address_format'];
						} else {
							$format = '{firstname} {lastname}' . "\n" . '{company}' . "\n" . '{address_1}' . "\n" . '{address_2}' . "\n" . '{city} {postcode}' . "\n" . '{zone}' . "\n" . '{country}';
						}
						
						$find = array(
							'{firstname}',
							'{lastname}',
							'{company}',
							'{address_1}',
							'{address_2}',
							'{city}',
							'{postcode}',
							'{zone}',
							'{zone_code}',
							'{country}'
						);
					
						$replace = array(
							'firstname' => $order_info['shipping_firstname'],
							'lastname'  => $order_info['shipping_lastname'],
							'company'   => $order_info['shipping_company'],
							'address_1' => $order_info['shipping_address_1'],
							'address_2' => $order_info['shipping_address_2'],
							'city'      => $order_info['shipping_city'],
							'postcode'  => $order_info['shipping_postcode'],
							'zone'      => $order_info['shipping_zone'],
							'zone_code' => $order_info['shipping_zone_code'],
							'country'   => $order_info['shipping_country']  
						);
					
						$template->data['shipping_address'] = str_replace(array("\r\n", "\r", "\n"), '<br />', preg_replace(array("/\s\s+/", "/\r\r+/", "/\n\n+/"), '<br />', trim(str_replace($find, $replace, $format))));

						if ($order_info['payment_address_format']) {
							$format = $order_info['payment_address_format'];
						} else {
							$format = '{firstname} {lastname}' . "\n" . '{company}' . "\n" . '{address_1}' . "\n" . '{address_2}' . "\n" . '{city} {postcode}' . "\n" . '{zone}' . "\n" . '{country}';
						}
						
						$find = array(
							'{firstname}',
							'{lastname}',
							'{company}',
							'{address_1}',
							'{address_2}',
							'{city}',
							'{postcode}',
							'{zone}',
							'{zone_code}',
							'{country}'
						);
					
						$replace = array(
							'firstname' => $order_info['payment_firstname'],
							'lastname'  => $order_info['payment_lastname'],
							'company'   => $order_info['payment_company'],
							'address_1' => $order_info['payment_address_1'],
							'address_2' => $order_info['payment_address_2'],
							'city'      => $order_info['payment_city'],
							'postcode'  => $order_info['payment_postcode'],
							'zone'      => $order_info['payment_zone'],
							'zone_code' => $order_info['payment_zone_code'],
							'country'   => $order_info['payment_country']  
						);
					
						$template->data['payment_address'] = str_replace(array("\r\n", "\r", "\n"), '<br />', preg_replace(array("/\s\s+/", "/\r\r+/", "/\n\n+/"), '<br />', trim(str_replace($find, $replace, $format))));
						
						$template->data['products'] = array();
							
						foreach ($order_product_query->rows as $product) {
							$option_data = array();
							
							$order_option_query = $this->db->query("SELECT * FROM " . DB_PREFIX . "order_option WHERE order_id = '" . (int)$order_id . "' AND order_product_id = '" . (int)$product['order_product_id'] . "'");
							
							foreach ($order_option_query->rows as $option) {
								if ($option['type'] != 'file') {
									$option_data[] = array(
										'name'  => $option['name'],
										'value' => (strlen($option['value']) > 20 ? substr($option['value'], 0, 20) . '..' : $option['value'])
									);
								} else {
									$filename = substr($option['value'], 0, strrpos($option['value'], '.'));
									
									$option_data[] = array(
										'name'  => $option['name'],
										'value' => (strlen($filename) > 20 ? substr($filename, 0, 20) . '..' : $filename)
									);	
								}
							}
						  
							$template->data['products'][] = array(
								'name'     => $product['name'],
								'model'    => $product['model'],
								'option'   => $option_data,
								'quantity' => $product['quantity'],
								'price'    => $this->currency->format($product['price'], $order_info['currency_code'], $order_info['currency_value']),
								'total'    => $this->currency->format($product['total'], $order_info['currency_code'], $order_info['currency_value'])
							);
						}
				
						$template->data['totals'] = $order_total_query->rows;
						
						if (file_exists(DIR_TEMPLATE . $this->config->get('config_template') . '/template/mail/order.tpl')) {
							$html = $template->fetch($this->config->get('config_template') . '/template/mail/order.tpl');
						} else {
							$html = $template->fetch('default/template/checkout/mail/order.tpl');
						}
						]]></add>
				</operation>
        </file>
</modification>

https://forum.opencart.com/viewtopic.php?t=45829#p224874

Allow you to change the admin notification email to the same level of detail as the customer receives.

OCA_Detailed Order Admin Email Notification(1.5.2) vQmod - worked on 1.5.6.4 OpenCart v1.5.x only - 2

module

XML