diff --git a/.phpstan.dist.baselines/argument.type.php b/.phpstan.dist.baselines/argument.type.php
index 0287e245aeb..f8ce0bb34e5 100644
--- a/.phpstan.dist.baselines/argument.type.php
+++ b/.phpstan.dist.baselines/argument.type.php
@@ -5826,11 +5826,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Observer.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $info of method Mage_Payment_Helper_Data::getInfoBlock() expects Mage_Payment_Model_Info, Mage_Sales_Model_Order_Payment|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $item of method Mage_Sales_Model_Order_Item::setParentItem() expects Mage_Sales_Model_Order_Item, Mage_Sales_Model_Order_Item|null given.',
     'count' => 1,
@@ -5841,11 +5836,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_App_Emulation::startEnvironmentEmulation() expects int, int|null given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_Email_Template_Mailer::setStoreId() expects int, int|null given.',
     'count' => 2,
@@ -5886,16 +5876,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $info of method Mage_Payment_Helper_Data::getInfoBlock() expects Mage_Payment_Model_Info, Mage_Sales_Model_Order_Payment|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_App_Emulation::startEnvironmentEmulation() expects int, int|null given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_Email_Template_Mailer::setStoreId() expects int, int|null given.',
     'count' => 2,
@@ -5911,11 +5891,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo/Config.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $info of method Mage_Payment_Helper_Data::getInfoBlock() expects Mage_Payment_Model_Info, Mage_Sales_Model_Order_Payment|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $invoiceId of method Mage_Sales_Model_Resource_Order_Invoice_Comment_Collection::setInvoiceFilter() expects int, int|string|null given.',
     'count' => 1,
@@ -5926,11 +5901,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_App_Emulation::startEnvironmentEmulation() expects int, int|null given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_Email_Template_Mailer::setStoreId() expects int, int|null given.',
     'count' => 2,
@@ -6066,11 +6036,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Pdf/Total/Default.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $info of method Mage_Payment_Helper_Data::getInfoBlock() expects Mage_Payment_Model_Info, Mage_Sales_Model_Order_Payment|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $shipmentId of method Mage_Sales_Model_Resource_Order_Shipment_Comment_Collection::setShipmentFilter() expects int, int|string|null given.',
     'count' => 1,
@@ -6086,11 +6051,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_App_Emulation::startEnvironmentEmulation() expects int, int|null given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Parameter #1 $storeId of method Mage_Core_Model_Email_Template_Mailer::setStoreId() expects int, int|null given.',
     'count' => 2,
diff --git a/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php b/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php
index 501368db3a1..5c9cc588b31 100644
--- a/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php
+++ b/.phpstan.dist.baselines/booleanAnd.leftNotBoolean.php
@@ -996,11 +996,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Checkout/Controller/Action.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in &&, array|false given on the left side.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Checkout/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in &&, Mage_Sales_Model_Quote_Address|null given on the left side.',
     'count' => 3,
@@ -1916,31 +1911,16 @@
     'count' => 2,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in &&, array|false given on the left side.',
-    'count' => 4,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in &&, null given on the left side.',
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Config.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in &&, array|bool given on the left side.',
-    'count' => 4,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in &&, float given on the left side.',
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo/Total/Discount.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in &&, array|bool given on the left side.',
-    'count' => 4,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in &&, float given on the left side.',
     'count' => 1,
@@ -1991,11 +1971,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Payment/Transaction.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in &&, array|false given on the left side.',
-    'count' => 4,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in &&, int|string|null given on the left side.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php b/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php
index 0977686bf4f..a85de1e0b66 100644
--- a/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php
+++ b/.phpstan.dist.baselines/booleanNot.exprNotBoolean.php
@@ -5751,11 +5751,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, array|false given.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in a negated boolean, int|string|null given.',
     'count' => 8,
@@ -5776,11 +5771,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Api.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, array|bool given.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in a negated boolean, int|string|null given.',
     'count' => 1,
@@ -5796,11 +5786,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo/Item.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, array|bool given.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in a negated boolean, int|string|null given.',
     'count' => 1,
@@ -5896,11 +5881,6 @@
     'count' => 3,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Payment/Transaction.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Only booleans are allowed in a negated boolean, array|false given.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Only booleans are allowed in a negated boolean, int<0, max> given.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/empty.notAllowed.php b/.phpstan.dist.baselines/empty.notAllowed.php
index f19a68924cd..85e73ce1228 100644
--- a/.phpstan.dist.baselines/empty.notAllowed.php
+++ b/.phpstan.dist.baselines/empty.notAllowed.php
@@ -1326,11 +1326,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Checkout/Helper/Cart.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Checkout/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
     'count' => 2,
@@ -2648,7 +2643,7 @@
 ];
 $ignoreErrors[] = [
     'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
-    'count' => 8,
+    'count' => 7,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
 ];
 $ignoreErrors[] = [
@@ -2656,21 +2651,11 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Config.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo/Api.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
-    'count' => 3,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
     'count' => 3,
@@ -2696,11 +2681,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Pdf/Shipment.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
-    'count' => 2,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Construct empty() is not allowed. Use more strict comparison.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/foreach.nonIterable.php b/.phpstan.dist.baselines/foreach.nonIterable.php
index ae5aed2efd2..35897645162 100644
--- a/.phpstan.dist.baselines/foreach.nonIterable.php
+++ b/.phpstan.dist.baselines/foreach.nonIterable.php
@@ -511,16 +511,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Block/Order/Totals.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Argument of an invalid type array|true supplied for foreach, only iterables are supported.',
-    'count' => 4,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Argument of an invalid type array|true supplied for foreach, only iterables are supported.',
-    'count' => 4,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Argument of an invalid type (iterable<Mage_Sales_Model_Order_Creditmemo>&Mage_Sales_Model_Resource_Order_Creditmemo_Collection)|false supplied for foreach, only iterables are supported.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/missingType.generics.php b/.phpstan.dist.baselines/missingType.generics.php
index 4109f7d7bc8..43142f37bbe 100644
--- a/.phpstan.dist.baselines/missingType.generics.php
+++ b/.phpstan.dist.baselines/missingType.generics.php
@@ -726,21 +726,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Rule/Model/Resource/Rule/Collection/Abstract.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Sales_Block_Order_Comments::getComments() return type with generic class Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract does not specify its types: T',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Block/Order/Comments.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'PHPDoc tag @var for variable $commentCollection contains generic class Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract but does not specify its types: T',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Block/Order/Comments.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Property Mage_Sales_Block_Order_Comments::$_commentCollection with generic class Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract does not specify its types: T',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Block/Order/Comments.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Sales_Block_Order_Details::getInvoices() return type with generic class Mage_Sales_Model_Resource_Order_Collection_Abstract does not specify its types: T',
     'count' => 1,
@@ -856,16 +841,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Entity/Sale/Collection.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Sales_Model_Order_Creditmemo::getCommentsCollection() return type with generic class Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract does not specify its types: T',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Sales_Model_Order_Invoice::getCommentsCollection() return type with generic class Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract does not specify its types: T',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Sales_Model_Resource_Order_Collection::addAddressFields() return type with generic class Mage_Sales_Model_Resource_Collection_Abstract does not specify its types: T',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/missingType.iterableValue.php b/.phpstan.dist.baselines/missingType.iterableValue.php
index cc25fc2958c..984423fdeaa 100644
--- a/.phpstan.dist.baselines/missingType.iterableValue.php
+++ b/.phpstan.dist.baselines/missingType.iterableValue.php
@@ -10486,11 +10486,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Checkout/Helper/Cart.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Checkout_Helper_Data::_getEmails() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Checkout/Helper/Data.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Checkout_Helper_Data::getRequiredAgreementIds() return type has no value type specified in iterable type array.',
     'count' => 1,
@@ -21836,11 +21831,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Sales_Model_Order::_getEmails() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Sales_Model_Order::getItemsCollection() has parameter $filterByTypes with no value type specified in iterable type array.',
     'count' => 1,
@@ -21921,11 +21911,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Config.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Sales_Model_Order_Creditmemo::_getEmails() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Sales_Model_Order_Creditmemo::getFilteredCollectionItems() has parameter $filter with no value type specified in iterable type array.',
     'count' => 1,
@@ -21991,11 +21976,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo/Api/V2.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Sales_Model_Order_Invoice::_getEmails() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Sales_Model_Order_Invoice::getStates() return type has no value type specified in iterable type array.',
     'count' => 1,
@@ -22246,11 +22226,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Pdf/Total/Default.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Method Mage_Sales_Model_Order_Shipment::_getEmails() return type has no value type specified in iterable type array.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Method Mage_Sales_Model_Order_Shipment_Api::_getCarriers() return type has no value type specified in iterable type array.',
     'count' => 1,
diff --git a/.phpstan.dist.baselines/notEqual.notAllowed.php b/.phpstan.dist.baselines/notEqual.notAllowed.php
index 110e4072b65..0422b94613b 100644
--- a/.phpstan.dist.baselines/notEqual.notAllowed.php
+++ b/.phpstan.dist.baselines/notEqual.notAllowed.php
@@ -2046,11 +2046,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Observer.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Loose comparison via "!=" between int|null and int|null is not allowed.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Loose comparison via "!=" between mixed and int|string|null is not allowed.',
     'count' => 2,
@@ -2071,11 +2066,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Loose comparison via "!=" between int|null and int|null is not allowed.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Loose comparison via "!=" between iterable<Mage_Sales_Model_Order_Creditmemo_Item>&Mage_Sales_Model_Resource_Order_Creditmemo_Item_Collection and null is not allowed.',
     'count' => 1,
@@ -2096,11 +2086,6 @@
     'count' => 3,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Creditmemo/Total/Shipping.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Loose comparison via "!=" between int|null and int|null is not allowed.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Invoice.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Loose comparison via "!=" between mixed and int is not allowed.',
     'count' => 3,
@@ -2141,11 +2126,6 @@
     'count' => 1,
     'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Pdf/Total/Default.php',
 ];
-$ignoreErrors[] = [
-    'rawMessage' => 'Loose comparison via "!=" between int|null and int|null is not allowed.',
-    'count' => 1,
-    'path' => __DIR__ . '/../app/code/core/Mage/Sales/Model/Order/Shipment.php',
-];
 $ignoreErrors[] = [
     'rawMessage' => 'Loose comparison via "!=" between mixed and int|string|null is not allowed.',
     'count' => 1,
diff --git a/app/code/core/Mage/Checkout/Helper/Data.php b/app/code/core/Mage/Checkout/Helper/Data.php
index 294bf962ffd..a12df9d7915 100644
--- a/app/code/core/Mage/Checkout/Helper/Data.php
+++ b/app/code/core/Mage/Checkout/Helper/Data.php
@@ -11,6 +11,7 @@
  * Checkout default helper
  *
  * @package    Mage_Checkout
+ * @phpstan-import-type ConfigStoreId from Mage
  */
 class Mage_Checkout_Helper_Data extends Mage_Core_Helper_Abstract
 {
@@ -186,7 +187,7 @@ public function sendPaymentFailedEmail($checkout, $message, $checkoutType = 'one
 
         $copyTo = $this->_getEmails('checkout/payment_failed/copy_to', $checkout->getStoreId());
         $copyMethod = Mage::getStoreConfig('checkout/payment_failed/copy_method', $checkout->getStoreId());
-        if ($copyTo && $copyMethod == 'bcc') {
+        if (is_array($copyTo) && $copyMethod == 'bcc') {
             $mailTemplate->addBcc($copyTo);
         }
 
@@ -198,7 +199,7 @@ public function sendPaymentFailedEmail($checkout, $message, $checkoutType = 'one
             ],
         ];
 
-        if ($copyTo && $copyMethod == 'copy') {
+        if (is_array($copyTo) && $copyMethod == 'copy') {
             foreach ($copyTo as $email) {
                 $sendTo[] = [
                     'email' => $email,
@@ -257,14 +258,14 @@ public function sendPaymentFailedEmail($checkout, $message, $checkoutType = 'one
     }
 
     /**
-     * @param  string      $configPath
-     * @param  int         $storeId
-     * @return array|false
+     * @param  string             $configPath
+     * @param  ConfigStoreId      $storeId
+     * @return false|list<string>
      */
     protected function _getEmails($configPath, $storeId)
     {
         $data = Mage::getStoreConfig($configPath, $storeId);
-        if (!empty($data)) {
+        if (is_string($data) && $data !== '') {
             return explode(',', $data);
         }
 
diff --git a/app/code/core/Mage/Payment/Block/Info.php b/app/code/core/Mage/Payment/Block/Info.php
index 29c181a34bf..977a0704112 100644
--- a/app/code/core/Mage/Payment/Block/Info.php
+++ b/app/code/core/Mage/Payment/Block/Info.php
@@ -8,11 +8,13 @@
  */
 
 /**
- * Base payment iformation block
+ * Base payment information block
  *
  * @package    Mage_Payment
  *
- * @method bool hasIsSecureMode()
+ * @method bool  hasIsSecureMode()
+ * @method $this setInfo(Mage_Payment_Model_Info $info)
+ * @method $this setIsSecureMode(bool $val)
  */
 class Mage_Payment_Block_Info extends Mage_Core_Block_Template
 {
diff --git a/app/code/core/Mage/Payment/Helper/Data.php b/app/code/core/Mage/Payment/Helper/Data.php
index 3db90cf190b..18427bf5817 100644
--- a/app/code/core/Mage/Payment/Helper/Data.php
+++ b/app/code/core/Mage/Payment/Helper/Data.php
@@ -125,7 +125,7 @@ public function getMethodFormBlock(Mage_Payment_Model_Method_Abstract $method)
     /**
      * Retrieve payment information block
      *
-     * @return Mage_Core_Block_Abstract
+     * @return Mage_Payment_Block_Info
      * @throws Mage_Core_Exception
      */
     public function getInfoBlock(Mage_Payment_Model_Info $info)
@@ -138,7 +138,7 @@ public function getInfoBlock(Mage_Payment_Model_Info $info)
             $block = new $className();
         }
 
-        /** @var Mage_Core_Block_Abstract $block */
+        /** @var Mage_Payment_Block_Info $block */
         $block->setInfo($info);
         return $block;
     }
diff --git a/app/code/core/Mage/Sales/Block/Order/Comments.php b/app/code/core/Mage/Sales/Block/Order/Comments.php
index 6e28ed4cca1..10b88704b78 100644
--- a/app/code/core/Mage/Sales/Block/Order/Comments.php
+++ b/app/code/core/Mage/Sales/Block/Order/Comments.php
@@ -22,7 +22,7 @@ class Mage_Sales_Block_Order_Comments extends Mage_Core_Block_Template
     /**
      * Current comments collection
      *
-     * @var null|Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract
+     * @var null|Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract<Mage_Sales_Model_Order_Comment_Abstract>
      */
     protected $_commentCollection;
 
@@ -52,7 +52,7 @@ public function getEntity()
     /**
      * Initialize model comments and return comment collection
      *
-     * @return Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract
+     * @return Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract<Mage_Sales_Model_Order_Comment_Abstract>
      */
     public function getComments()
     {
@@ -68,7 +68,7 @@ public function getComments()
                 Mage::throwException(Mage::helper('sales')->__('Invalid entity model'));
             }
 
-            /** @var Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract $commentCollection */
+            /** @var Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract<Mage_Sales_Model_Order_Comment_Abstract> $commentCollection */
             $commentCollection = Mage::getResourceModel($collectionClass);
             $this->_commentCollection = $commentCollection;
             $this->_commentCollection->setParentFilter($entity)
diff --git a/app/code/core/Mage/Sales/Model/Abstract.php b/app/code/core/Mage/Sales/Model/Abstract.php
index 1e15e287882..0702b6cbd03 100644
--- a/app/code/core/Mage/Sales/Model/Abstract.php
+++ b/app/code/core/Mage/Sales/Model/Abstract.php
@@ -17,8 +17,10 @@
  * @method bool                                     getForceUpdateGridRecords()
  * @method Mage_Sales_Model_Resource_Order_Abstract getResource()
  * @method Mage_Customer_Model_Address_Abstract     getShippingAddress()
+ * @method int                                      getStoreId()
  * @method $this                                    setBillingAddress(Mage_Customer_Model_Address_Abstract $address)
  * @method $this                                    setShippingAddress(Mage_Customer_Model_Address_Abstract $address)
+ * @method $this                                    setStoreId(int $value)
  * @method $this                                    setTransactionId(int $value)
  */
 abstract class Mage_Sales_Model_Abstract extends Mage_Core_Model_Abstract
@@ -74,4 +76,59 @@ public function getCreatedAtStoreDate()
             true,
         );
     }
+
+    protected function getMailer(): Mage_Core_Model_Email_Template_Mailer
+    {
+        /**
+         * @var Mage_Core_Model_Email_Template_Mailer $mailer
+         */
+        $mailer = Mage::getModel('core/email_template_mailer');
+        return $mailer;
+    }
+
+    /**
+     * @throws Mage_Core_Exception
+     * @throws Mage_Core_Model_Store_Exception
+     */
+    protected function getPaymentBlockHtml(Mage_Sales_Model_Order $order): ?string
+    {
+        $storeId = $order->getStore()->getId();
+        $payment = $order->getPayment();
+        if (!is_null($storeId) && $payment instanceof Mage_Payment_Model_Info) {
+            // Start store emulation process
+            if ($storeId !== Mage::app()->getStore()->getId()) {
+                $appEmulation = Mage::getSingleton('core/app_emulation');
+                $initialEnvironmentInfo = $appEmulation->startEnvironmentEmulation($storeId);
+            }
+
+            try {
+                // Retrieve specified view block from appropriate design package (depends on emulated store)
+                $paymentBlock = Mage::helper('payment')->getInfoBlock($payment)
+                    ->setIsSecureMode(true);
+                $paymentBlock->getMethod()->setStore($storeId);
+                return $paymentBlock->toHtml();
+            } finally {
+                // Stop store emulation process
+                if (isset($appEmulation, $initialEnvironmentInfo)) {
+                    $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
+                }
+            }
+        }
+
+        return null;
+    }
+
+    /**
+     * @param  string             $configPath
+     * @return false|list<string>
+     */
+    protected function _getEmails($configPath)
+    {
+        $data = Mage::getStoreConfig($configPath, $this->getStoreId());
+        if (is_string($data) && $data !== '') {
+            return explode(',', $data);
+        }
+
+        return false;
+    }
 }
diff --git a/app/code/core/Mage/Sales/Model/Order.php b/app/code/core/Mage/Sales/Model/Order.php
index 6c27fa18837..925e25130f5 100644
--- a/app/code/core/Mage/Sales/Model/Order.php
+++ b/app/code/core/Mage/Sales/Model/Order.php
@@ -153,7 +153,6 @@
  * @method string                                     getState()
  * @method string                                     getStatus()
  * @method string                                     getStoreCurrencyCode()
- * @method int                                        getStoreId()
  * @method string                                     getStoreName()
  * @method float                                      getStoreToBaseRate()
  * @method float                                      getStoreToOrderRate()
@@ -302,7 +301,6 @@
  * @method $this                                      setShippingTaxRefunded(float $value)
  * @method $this                                      setStatus(string $value)
  * @method $this                                      setStoreCurrencyCode(string $value)
- * @method $this                                      setStoreId(int $value)
  * @method $this                                      setStoreName(string $value)
  * @method $this                                      setStoreToBaseRate(float $value)
  * @method $this                                      setStoreToOrderRate(float $value)
@@ -1405,32 +1403,7 @@ public function queueNewOrderEmail($forceMode = false)
         $copyTo = $this->_getEmails(self::XML_PATH_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_EMAIL_COPY_METHOD, $storeId);
 
-        // Start store emulation process
-        if ($storeId != Mage::app()->getStore()->getId()) {
-            /** @var Mage_Core_Model_App_Emulation $appEmulation */
-            $appEmulation = Mage::getSingleton('core/app_emulation');
-            $initialEnvironmentInfo = $appEmulation->startEnvironmentEmulation($storeId);
-        }
-
-        try {
-            // Retrieve specified view block from appropriate design package (depends on emulated store)
-            $paymentBlock = Mage::helper('payment')->getInfoBlock($this->getPayment())
-                ->setIsSecureMode(true);
-            $paymentBlock->getMethod()->setStore($storeId);
-            $paymentBlockHtml = $paymentBlock->toHtml();
-        } catch (Exception $exception) {
-            // Stop store emulation process
-            if (isset($appEmulation, $initialEnvironmentInfo)) {
-                $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-            }
-
-            throw $exception;
-        }
-
-        // Stop store emulation process
-        if (isset($appEmulation, $initialEnvironmentInfo)) {
-            $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-        }
+        $paymentBlockHtml = $this->getPaymentBlockHtml($this);
 
         // Retrieve corresponding email template id and customer name
         if ($this->getCustomerIsGuest()) {
@@ -1441,12 +1414,11 @@ public function queueNewOrderEmail($forceMode = false)
             $customerName = $this->getCustomerName();
         }
 
-        /** @var Mage_Core_Model_Email_Template_Mailer $mailer */
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         /** @var Mage_Core_Model_Email_Info $emailInfo */
         $emailInfo = Mage::getModel('core/email_info');
         $emailInfo->addTo($this->getCurrentCustomerEmail(), $customerName);
-        if ($copyTo && $copyMethod == 'bcc') {
+        if (is_array($copyTo) && $copyMethod == 'bcc') {
             // Add bcc to customer email
             foreach ($copyTo as $email) {
                 $emailInfo->addBcc($email);
@@ -1456,7 +1428,7 @@ public function queueNewOrderEmail($forceMode = false)
         $mailer->addEmailInfo($emailInfo);
 
         // Email copies are sent as separated emails if their copy method is 'copy'
-        if ($copyTo && $copyMethod == 'copy') {
+        if (is_array($copyTo) && $copyMethod == 'copy') {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -1521,7 +1493,7 @@ public function queueOrderUpdateEmail($notifyCustomer = true, $comment = '', $fo
         $copyTo = $this->_getEmails(self::XML_PATH_UPDATE_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_UPDATE_EMAIL_COPY_METHOD, $storeId);
         // Check if at least one recipient is found
-        if (!$notifyCustomer && !$copyTo) {
+        if (!$notifyCustomer && !is_array($copyTo)) {
             return $this;
         }
 
@@ -1534,13 +1506,12 @@ public function queueOrderUpdateEmail($notifyCustomer = true, $comment = '', $fo
             $customerName = $this->getCustomerName();
         }
 
-        /** @var Mage_Core_Model_Email_Template_Mailer $mailer */
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         if ($notifyCustomer) {
             /** @var Mage_Core_Model_Email_Info $emailInfo */
             $emailInfo = Mage::getModel('core/email_info');
             $emailInfo->addTo($this->getCurrentCustomerEmail(), $customerName);
-            if ($copyTo && $copyMethod == 'bcc') {
+            if (is_array($copyTo) && $copyMethod == 'bcc') {
                 // Add bcc to customer email
                 foreach ($copyTo as $email) {
                     $emailInfo->addBcc($email);
@@ -1552,7 +1523,7 @@ public function queueOrderUpdateEmail($notifyCustomer = true, $comment = '', $fo
 
         // Email copies are sent as separated emails if their copy method is
         // 'copy' or a customer should not be notified
-        if ($copyTo && ($copyMethod == 'copy' || !$notifyCustomer)) {
+        if (is_array($copyTo) && ($copyMethod == 'copy' || !$notifyCustomer)) {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -1595,20 +1566,6 @@ public function sendOrderUpdateEmail($notifyCustomer = true, $comment = '')
         return $this;
     }
 
-    /**
-     * @param  string      $configPath
-     * @return array|false
-     */
-    protected function _getEmails($configPath)
-    {
-        $data = Mage::getStoreConfig($configPath, $this->getStoreId());
-        if (!empty($data)) {
-            return explode(',', $data);
-        }
-
-        return false;
-    }
-
     /*********************** ADDRESSES ***************************/
 
     /**
diff --git a/app/code/core/Mage/Sales/Model/Order/Comment/Abstract.php b/app/code/core/Mage/Sales/Model/Order/Comment/Abstract.php
new file mode 100644
index 00000000000..20d95dbaeb7
--- /dev/null
+++ b/app/code/core/Mage/Sales/Model/Order/Comment/Abstract.php
@@ -0,0 +1,27 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright  For copyright and license information, read the COPYING.txt file.
+ * @link       /COPYING.txt
+ * @license    Open Software License (OSL 3.0)
+ * @package    Mage_Sales
+ */
+
+/**
+ * Class Mage_Sales_Model_Order_Comment_Abstract
+ *
+ * @package    Mage_Sales
+ *
+ * @method string getComment()
+ * @method int    getIsCustomerNotified()
+ * @method int    getIsVisibleOnFront()
+ * @method int    getParentId()
+ * @method $this  setComment(string $value)
+ * @method $this  setIsCustomerNotified(int $value)
+ * @method $this  setIsVisibleOnFront(int $value)
+ * @method $this  setParentId(int $value)
+ * @method $this  setStoreId(int $value)
+ */
+abstract class Mage_Sales_Model_Order_Comment_Abstract extends Mage_Sales_Model_Abstract {}
diff --git a/app/code/core/Mage/Sales/Model/Order/Creditmemo.php b/app/code/core/Mage/Sales/Model/Order/Creditmemo.php
index 52111ca9440..504e112e358 100644
--- a/app/code/core/Mage/Sales/Model/Order/Creditmemo.php
+++ b/app/code/core/Mage/Sales/Model/Order/Creditmemo.php
@@ -114,7 +114,6 @@
  * @method $this                                                 setShippingTaxAmount(float $value)
  * @method $this                                                 setState(int $value)
  * @method $this                                                 setStoreCurrencyCode(string $value)
- * @method $this                                                 setStoreId(int $value)
  * @method $this                                                 setStoreToBaseRate(float $value)
  * @method $this                                                 setStoreToOrderRate(float $value)
  * @method $this                                                 setSubtotal(float $value)
@@ -125,6 +124,15 @@
  */
 class Mage_Sales_Model_Order_Creditmemo extends Mage_Sales_Model_Abstract
 {
+    public const ENTITY                                = 'creditmemo';
+
+    /**
+     * Event type names for order emails
+     */
+    public const EMAIL_EVENT_NAME_NEW_CREDITMEMO    = 'new_creditmemo';
+
+    public const EMAIL_EVENT_NAME_UPDATE_CREDITMEMO = 'update_creditmemo';
+
     public const STATE_OPEN        = 1;
 
     public const STATE_REFUNDED    = 2;
@@ -734,8 +742,8 @@ public function addComment($comment, $notify = false, $visibleOnFront = false)
     }
 
     /**
-     * @param  bool                                                        $reload
-     * @return Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract
+     * @param  bool                                                          $reload
+     * @return Mage_Sales_Model_Resource_Order_Creditmemo_Comment_Collection
      * @throws Mage_Core_Exception
      */
     public function getCommentsCollection($reload = false)
@@ -782,35 +790,11 @@ public function sendEmail($notifyCustomer = true, $comment = '')
         $copyTo = $this->_getEmails(self::XML_PATH_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_EMAIL_COPY_METHOD, $storeId);
         // Check if at least one recipient is found
-        if (!$notifyCustomer && !$copyTo) {
+        if (!$notifyCustomer && !is_array($copyTo)) {
             return $this;
         }
 
-        // Start store emulation process
-        if ($storeId != Mage::app()->getStore()->getId()) {
-            $appEmulation = Mage::getSingleton('core/app_emulation');
-            $initialEnvironmentInfo = $appEmulation->startEnvironmentEmulation($storeId);
-        }
-
-        try {
-            // Retrieve specified view block from appropriate design package (depends on emulated store)
-            $paymentBlock = Mage::helper('payment')->getInfoBlock($order->getPayment())
-                ->setIsSecureMode(true);
-            $paymentBlock->getMethod()->setStore($storeId);
-            $paymentBlockHtml = $paymentBlock->toHtml();
-        } catch (Exception $exception) {
-            // Stop store emulation process
-            if (isset($appEmulation, $initialEnvironmentInfo)) {
-                $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-            }
-
-            throw $exception;
-        }
-
-        // Stop store emulation process
-        if (isset($appEmulation, $initialEnvironmentInfo)) {
-            $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-        }
+        $paymentBlockHtml = $this->getPaymentBlockHtml($order);
 
         // Retrieve corresponding email template id and customer name
         if ($order->getCustomerIsGuest()) {
@@ -821,11 +805,11 @@ public function sendEmail($notifyCustomer = true, $comment = '')
             $customerName = $order->getCustomerName();
         }
 
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         if ($notifyCustomer) {
             $emailInfo = Mage::getModel('core/email_info');
             $emailInfo->addTo($order->getCurrentCustomerEmail(), $customerName);
-            if ($copyTo && $copyMethod === 'bcc') {
+            if (is_array($copyTo) && $copyMethod === 'bcc') {
                 // Add bcc to customer email
                 foreach ($copyTo as $email) {
                     $emailInfo->addBcc($email);
@@ -836,7 +820,7 @@ public function sendEmail($notifyCustomer = true, $comment = '')
         }
 
         // Email copies are sent as separated emails if their copy method is 'copy' or a customer should not be notified
-        if ($copyTo && ($copyMethod === 'copy' || !$notifyCustomer)) {
+        if (is_array($copyTo) && ($copyMethod === 'copy' || !$notifyCustomer)) {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -855,7 +839,15 @@ public function sendEmail($notifyCustomer = true, $comment = '')
             'billing'      => $order->getBillingAddress(),
             'payment_html' => $paymentBlockHtml,
         ]);
-        $mailer->send();
+
+        /** @var Mage_Core_Model_Email_Queue $emailQueue */
+        $emailQueue = Mage::getModel('core/email_queue');
+        $emailQueue->setEntityId($this->getId())
+            ->setEntityType(self::ENTITY)
+            ->setEventType(self::EMAIL_EVENT_NAME_NEW_CREDITMEMO)
+            ->setIsForceCheck(true);
+
+        $mailer->setQueue($emailQueue)->send();
 
         if ($notifyCustomer) {
             $this->setEmailSent(true);
@@ -886,7 +878,7 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
         $copyTo = $this->_getEmails(self::XML_PATH_UPDATE_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_UPDATE_EMAIL_COPY_METHOD, $storeId);
         // Check if at least one recipient is found
-        if (!$notifyCustomer && !$copyTo) {
+        if (!$notifyCustomer && !is_array($copyTo)) {
             return $this;
         }
 
@@ -899,11 +891,11 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
             $customerName = $order->getCustomerName();
         }
 
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         if ($notifyCustomer) {
             $emailInfo = Mage::getModel('core/email_info');
             $emailInfo->addTo($order->getCurrentCustomerEmail(), $customerName);
-            if ($copyTo && $copyMethod === 'bcc') {
+            if (is_array($copyTo) && $copyMethod === 'bcc') {
                 // Add bcc to customer email
                 foreach ($copyTo as $email) {
                     $emailInfo->addBcc($email);
@@ -914,7 +906,7 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
         }
 
         // Email copies are sent as separated emails if their copy method is 'copy' or a customer should not be notified
-        if ($copyTo && ($copyMethod === 'copy' || !$notifyCustomer)) {
+        if (is_array($copyTo) && ($copyMethod === 'copy' || !$notifyCustomer)) {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -932,23 +924,17 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
             'comment'    => $comment,
             'billing'    => $order->getBillingAddress(),
         ]);
-        $mailer->send();
 
-        return $this;
-    }
+        /** @var Mage_Core_Model_Email_Queue $emailQueue */
+        $emailQueue = Mage::getModel('core/email_queue');
+        $emailQueue->setEntityId($this->getId())
+            ->setEntityType(self::ENTITY)
+            ->setEventType(self::EMAIL_EVENT_NAME_UPDATE_CREDITMEMO)
+            ->setIsForceCheck(true);
 
-    /**
-     * @param  string     $configPath
-     * @return array|bool
-     */
-    protected function _getEmails($configPath)
-    {
-        $data = Mage::getStoreConfig($configPath, $this->getStoreId());
-        if (!empty($data)) {
-            return explode(',', $data);
-        }
+        $mailer->setQueue($emailQueue)->send();
 
-        return false;
+        return $this;
     }
 
     /**
diff --git a/app/code/core/Mage/Sales/Model/Order/Creditmemo/Comment.php b/app/code/core/Mage/Sales/Model/Order/Creditmemo/Comment.php
index 3104ca00c03..492c475d23b 100644
--- a/app/code/core/Mage/Sales/Model/Order/Creditmemo/Comment.php
+++ b/app/code/core/Mage/Sales/Model/Order/Creditmemo/Comment.php
@@ -12,19 +12,10 @@
  *
  * @method Mage_Sales_Model_Resource_Order_Creditmemo_Comment            _getResource()
  * @method Mage_Sales_Model_Resource_Order_Creditmemo_Comment_Collection getCollection()
- * @method string                                                        getComment()
- * @method int                                                           getIsCustomerNotified()
- * @method int                                                           getIsVisibleOnFront()
- * @method int                                                           getParentId()
  * @method Mage_Sales_Model_Resource_Order_Creditmemo_Comment            getResource()
  * @method Mage_Sales_Model_Resource_Order_Creditmemo_Comment_Collection getResourceCollection()
- * @method $this                                                         setComment(string $value)
- * @method $this                                                         setIsCustomerNotified(int $value)
- * @method $this                                                         setIsVisibleOnFront(int $value)
- * @method $this                                                         setParentId(int $value)
- * @method $this                                                         setStoreId(int $value)
  */
-class Mage_Sales_Model_Order_Creditmemo_Comment extends Mage_Sales_Model_Abstract
+class Mage_Sales_Model_Order_Creditmemo_Comment extends Mage_Sales_Model_Order_Comment_Abstract
 {
     /**
      * Creditmemo instance
diff --git a/app/code/core/Mage/Sales/Model/Order/Invoice.php b/app/code/core/Mage/Sales/Model/Order/Invoice.php
index f88a7337d73..70a72405e8e 100644
--- a/app/code/core/Mage/Sales/Model/Order/Invoice.php
+++ b/app/code/core/Mage/Sales/Model/Order/Invoice.php
@@ -50,7 +50,6 @@
  * @method float                                              getShippingTaxAmount()
  * @method int                                                getState()
  * @method string                                             getStoreCurrencyCode()
- * @method int                                                getStoreId()
  * @method float                                              getStoreToBaseRate()
  * @method float                                              getStoreToOrderRate()
  * @method float                                              getSubtotal()
@@ -94,7 +93,6 @@
  * @method $this                                              setShippingTaxAmount(float $value)
  * @method $this                                              setState(int $value)
  * @method $this                                              setStoreCurrencyCode(string $value)
- * @method $this                                              setStoreId(int $value)
  * @method $this                                              setStoreToBaseRate(float $value)
  * @method $this                                              setStoreToOrderRate(float $value)
  * @method $this                                              setSubtotal(float $value)
@@ -105,6 +103,15 @@
  */
 class Mage_Sales_Model_Order_Invoice extends Mage_Sales_Model_Abstract
 {
+    public const ENTITY                                = 'invoice';
+
+    /**
+     * Event type names for order emails
+     */
+    public const EMAIL_EVENT_NAME_NEW_INVOICE    = 'new_invoice';
+
+    public const EMAIL_EVENT_NAME_UPDATE_INVOICE = 'update_invoice';
+
     /**
      * Invoice states
      */
@@ -229,7 +236,7 @@ public function loadByIncrementId($incrementId)
             ->addAttributeToFilter('increment_id', $incrementId)
             ->getAllIds();
 
-        if (!empty($ids)) {
+        if ($ids !== []) {
             reset($ids);
             $this->load(current($ids));
         }
@@ -546,7 +553,7 @@ public function roundPrice($price, $type = 'regular', $negative = false)
      */
     public function getItemsCollection()
     {
-        if (empty($this->_items)) {
+        if (is_null($this->_items)) {
             $this->_items = Mage::getResourceModel('sales/order_invoice_item_collection')
                 ->setInvoiceFilter($this->getId());
 
@@ -766,8 +773,8 @@ public function addComment($comment, $notify = false, $visibleOnFront = false)
     }
 
     /**
-     * @param  bool                                                        $reload
-     * @return Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract
+     * @param  bool                                                       $reload
+     * @return Mage_Sales_Model_Resource_Order_Invoice_Comment_Collection
      */
     public function getCommentsCollection($reload = false)
     {
@@ -811,35 +818,11 @@ public function sendEmail($notifyCustomer = true, $comment = '')
         $copyTo = $this->_getEmails(self::XML_PATH_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_EMAIL_COPY_METHOD, $storeId);
         // Check if at least one recipient is found
-        if (!$notifyCustomer && !$copyTo) {
+        if (!$notifyCustomer && !is_array($copyTo)) {
             return $this;
         }
 
-        // Start store emulation process
-        if ($storeId != Mage::app()->getStore()->getId()) {
-            $appEmulation = Mage::getSingleton('core/app_emulation');
-            $initialEnvironmentInfo = $appEmulation->startEnvironmentEmulation($storeId);
-        }
-
-        try {
-            // Retrieve specified view block from appropriate design package (depends on emulated store)
-            $paymentBlock = Mage::helper('payment')->getInfoBlock($order->getPayment())
-                ->setIsSecureMode(true);
-            $paymentBlock->getMethod()->setStore($storeId);
-            $paymentBlockHtml = $paymentBlock->toHtml();
-        } catch (Exception $exception) {
-            // Stop store emulation process
-            if (isset($appEmulation, $initialEnvironmentInfo)) {
-                $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-            }
-
-            throw $exception;
-        }
-
-        // Stop store emulation process
-        if (isset($appEmulation, $initialEnvironmentInfo)) {
-            $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-        }
+        $paymentBlockHtml = $this->getPaymentBlockHtml($order);
 
         // Retrieve corresponding email template id and customer name
         if ($order->getCustomerIsGuest()) {
@@ -850,11 +833,11 @@ public function sendEmail($notifyCustomer = true, $comment = '')
             $customerName = $order->getCustomerName();
         }
 
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         if ($notifyCustomer) {
             $emailInfo = Mage::getModel('core/email_info');
             $emailInfo->addTo($order->getCurrentCustomerEmail(), $customerName);
-            if ($copyTo && $copyMethod == 'bcc') {
+            if (is_array($copyTo) && $copyMethod == 'bcc') {
                 // Add bcc to customer email
                 foreach ($copyTo as $email) {
                     $emailInfo->addBcc($email);
@@ -865,7 +848,7 @@ public function sendEmail($notifyCustomer = true, $comment = '')
         }
 
         // Email copies are sent as separated emails if their copy method is 'copy' or a customer should not be notified
-        if ($copyTo && ($copyMethod == 'copy' || !$notifyCustomer)) {
+        if (is_array($copyTo) && ($copyMethod == 'copy' || !$notifyCustomer)) {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -884,7 +867,15 @@ public function sendEmail($notifyCustomer = true, $comment = '')
             'billing'      => $order->getBillingAddress(),
             'payment_html' => $paymentBlockHtml,
         ]);
-        $mailer->send();
+
+        /** @var Mage_Core_Model_Email_Queue $emailQueue */
+        $emailQueue = Mage::getModel('core/email_queue');
+        $emailQueue->setEntityId($this->getId())
+            ->setEntityType(self::ENTITY)
+            ->setEventType(self::EMAIL_EVENT_NAME_NEW_INVOICE)
+            ->setIsForceCheck(true);
+
+        $mailer->setQueue($emailQueue)->send();
 
         if ($notifyCustomer) {
             $this->setEmailSent(true);
@@ -914,7 +905,7 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
         $copyTo = $this->_getEmails(self::XML_PATH_UPDATE_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_UPDATE_EMAIL_COPY_METHOD, $storeId);
         // Check if at least one recipient is found
-        if (!$notifyCustomer && !$copyTo) {
+        if (!$notifyCustomer && !is_array($copyTo)) {
             return $this;
         }
 
@@ -927,11 +918,11 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
             $customerName = $order->getCustomerName();
         }
 
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         if ($notifyCustomer) {
             $emailInfo = Mage::getModel('core/email_info');
             $emailInfo->addTo($order->getCurrentCustomerEmail(), $customerName);
-            if ($copyTo && $copyMethod == 'bcc') {
+            if (is_array($copyTo) && $copyMethod == 'bcc') {
                 // Add bcc to customer email
                 foreach ($copyTo as $email) {
                     $emailInfo->addBcc($email);
@@ -942,7 +933,7 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
         }
 
         // Email copies are sent as separated emails if their copy method is 'copy' or a customer should not be notified
-        if ($copyTo && ($copyMethod == 'copy' || !$notifyCustomer)) {
+        if (is_array($copyTo) && ($copyMethod == 'copy' || !$notifyCustomer)) {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -960,23 +951,17 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
             'comment'      => $comment,
             'billing'      => $order->getBillingAddress(),
         ]);
-        $mailer->send();
 
-        return $this;
-    }
+        /** @var Mage_Core_Model_Email_Queue $emailQueue */
+        $emailQueue = Mage::getModel('core/email_queue');
+        $emailQueue->setEntityId($this->getId())
+            ->setEntityType(self::ENTITY)
+            ->setEventType(self::EMAIL_EVENT_NAME_UPDATE_INVOICE)
+            ->setIsForceCheck(true);
 
-    /**
-     * @param  string     $configPath
-     * @return array|bool
-     */
-    protected function _getEmails($configPath)
-    {
-        $data = Mage::getStoreConfig($configPath, $this->getStoreId());
-        if (!empty($data)) {
-            return explode(',', $data);
-        }
+        $mailer->setQueue($emailQueue)->send();
 
-        return false;
+        return $this;
     }
 
     /**
diff --git a/app/code/core/Mage/Sales/Model/Order/Invoice/Comment.php b/app/code/core/Mage/Sales/Model/Order/Invoice/Comment.php
index cb23bbc0823..eb6b1bd2054 100644
--- a/app/code/core/Mage/Sales/Model/Order/Invoice/Comment.php
+++ b/app/code/core/Mage/Sales/Model/Order/Invoice/Comment.php
@@ -12,19 +12,10 @@
  *
  * @method Mage_Sales_Model_Resource_Order_Invoice_Comment            _getResource()
  * @method Mage_Sales_Model_Resource_Order_Invoice_Comment_Collection getCollection()
- * @method string                                                     getComment()
- * @method int                                                        getIsCustomerNotified()
- * @method int                                                        getIsVisibleOnFront()
- * @method int                                                        getParentId()
  * @method Mage_Sales_Model_Resource_Order_Invoice_Comment            getResource()
  * @method Mage_Sales_Model_Resource_Order_Invoice_Comment_Collection getResourceCollection()
- * @method $this                                                      setComment(string $value)
- * @method $this                                                      setIsCustomerNotified(int $value)
- * @method $this                                                      setIsVisibleOnFront(int $value)
- * @method $this                                                      setParentId(int $value)
- * @method $this                                                      setStoreId(int $value)
  */
-class Mage_Sales_Model_Order_Invoice_Comment extends Mage_Sales_Model_Abstract
+class Mage_Sales_Model_Order_Invoice_Comment extends Mage_Sales_Model_Order_Comment_Abstract
 {
     /**
      * Invoice instance
diff --git a/app/code/core/Mage/Sales/Model/Order/Shipment.php b/app/code/core/Mage/Sales/Model/Order/Shipment.php
index b9fcd70a238..b19886c7207 100644
--- a/app/code/core/Mage/Sales/Model/Order/Shipment.php
+++ b/app/code/core/Mage/Sales/Model/Order/Shipment.php
@@ -24,7 +24,6 @@
  * @method Mage_Sales_Model_Resource_Order_Shipment_Collection getResourceCollection()
  * @method int                                                 getShipmentStatus()
  * @method int                                                 getShippingAddressId()
- * @method int                                                 getStoreId()
  * @method float                                               getTotalQty()
  * @method float                                               getTotalWeight()
  * @method $this                                               setBillingAddressId(int $value)
@@ -35,12 +34,20 @@
  * @method $this                                               setPackages(string $value)
  * @method $this                                               setShipmentStatus(int $value)
  * @method $this                                               setShippingAddressId(int $value)
- * @method $this                                               setStoreId(int $value)
  * @method $this                                               setTotalQty(float $value)
  * @method $this                                               setTotalWeight(float $value)
  */
 class Mage_Sales_Model_Order_Shipment extends Mage_Sales_Model_Abstract
 {
+    public const ENTITY                                = 'shipment';
+
+    /**
+     * Event type names for order emails
+     */
+    public const EMAIL_EVENT_NAME_NEW_SHIPMENT    = 'new_shipment';
+
+    public const EMAIL_EVENT_NAME_UPDATE_SHIPMENT = 'update_shipment';
+
     public const STATUS_NEW    = 1;
 
     public const XML_PATH_EMAIL_TEMPLATE               = 'sales_email/shipment/template';
@@ -130,7 +137,7 @@ public function loadByIncrementId($incrementId)
             ->addAttributeToFilter('increment_id', $incrementId)
             ->getAllIds();
 
-        if (!empty($ids)) {
+        if ($ids !== []) {
             reset($ids);
             $this->load(current($ids));
         }
@@ -443,35 +450,11 @@ public function sendEmail($notifyCustomer = true, $comment = '')
         $copyTo = $this->_getEmails(self::XML_PATH_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_EMAIL_COPY_METHOD, $storeId);
         // Check if at least one recipient is found
-        if (!$notifyCustomer && !$copyTo) {
+        if (!$notifyCustomer && !is_array($copyTo)) {
             return $this;
         }
 
-        // Start store emulation process
-        if ($storeId != Mage::app()->getStore()->getId()) {
-            $appEmulation = Mage::getSingleton('core/app_emulation');
-            $initialEnvironmentInfo = $appEmulation->startEnvironmentEmulation($storeId);
-        }
-
-        try {
-            // Retrieve specified view block from appropriate design package (depends on emulated store)
-            $paymentBlock = Mage::helper('payment')->getInfoBlock($order->getPayment())
-                ->setIsSecureMode(true);
-            $paymentBlock->getMethod()->setStore($storeId);
-            $paymentBlockHtml = $paymentBlock->toHtml();
-        } catch (Exception $exception) {
-            // Stop store emulation process
-            if (isset($appEmulation, $initialEnvironmentInfo)) {
-                $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-            }
-
-            throw $exception;
-        }
-
-        // Stop store emulation process
-        if (isset($appEmulation, $initialEnvironmentInfo)) {
-            $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);
-        }
+        $paymentBlockHtml = $this->getPaymentBlockHtml($order);
 
         // Retrieve corresponding email template id and customer name
         if ($order->getCustomerIsGuest()) {
@@ -482,11 +465,11 @@ public function sendEmail($notifyCustomer = true, $comment = '')
             $customerName = $order->getCustomerName();
         }
 
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         if ($notifyCustomer) {
             $emailInfo = Mage::getModel('core/email_info');
             $emailInfo->addTo($order->getCurrentCustomerEmail(), $customerName);
-            if ($copyTo && $copyMethod == 'bcc') {
+            if (is_array($copyTo) && $copyMethod == 'bcc') {
                 // Add bcc to customer email
                 foreach ($copyTo as $email) {
                     $emailInfo->addBcc($email);
@@ -497,7 +480,7 @@ public function sendEmail($notifyCustomer = true, $comment = '')
         }
 
         // Email copies are sent as separated emails if their copy method is 'copy' or a customer should not be notified
-        if ($copyTo && ($copyMethod == 'copy' || !$notifyCustomer)) {
+        if (is_array($copyTo) && ($copyMethod == 'copy' || !$notifyCustomer)) {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -516,7 +499,15 @@ public function sendEmail($notifyCustomer = true, $comment = '')
             'billing'      => $order->getBillingAddress(),
             'payment_html' => $paymentBlockHtml,
         ]);
-        $mailer->send();
+
+        /** @var Mage_Core_Model_Email_Queue $emailQueue */
+        $emailQueue = Mage::getModel('core/email_queue');
+        $emailQueue->setEntityId($this->getId())
+            ->setEntityType(self::ENTITY)
+            ->setEventType(self::EMAIL_EVENT_NAME_NEW_SHIPMENT)
+            ->setIsForceCheck(true);
+
+        $mailer->setQueue($emailQueue)->send();
 
         return $this;
     }
@@ -541,7 +532,7 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
         $copyTo = $this->_getEmails(self::XML_PATH_UPDATE_EMAIL_COPY_TO);
         $copyMethod = Mage::getStoreConfig(self::XML_PATH_UPDATE_EMAIL_COPY_METHOD, $storeId);
         // Check if at least one recipient is found
-        if (!$notifyCustomer && !$copyTo) {
+        if (!$notifyCustomer && !is_array($copyTo)) {
             return $this;
         }
 
@@ -554,11 +545,11 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
             $customerName = $order->getCustomerName();
         }
 
-        $mailer = Mage::getModel('core/email_template_mailer');
+        $mailer = $this->getMailer();
         if ($notifyCustomer) {
             $emailInfo = Mage::getModel('core/email_info');
             $emailInfo->addTo($order->getCurrentCustomerEmail(), $customerName);
-            if ($copyTo && $copyMethod == 'bcc') {
+            if (is_array($copyTo) && $copyMethod == 'bcc') {
                 // Add bcc to customer email
                 foreach ($copyTo as $email) {
                     $emailInfo->addBcc($email);
@@ -569,7 +560,7 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
         }
 
         // Email copies are sent as separated emails if their copy method is 'copy' or a customer should not be notified
-        if ($copyTo && ($copyMethod == 'copy' || !$notifyCustomer)) {
+        if (is_array($copyTo) && ($copyMethod == 'copy' || !$notifyCustomer)) {
             foreach ($copyTo as $email) {
                 $emailInfo = Mage::getModel('core/email_info');
                 $emailInfo->addTo($email);
@@ -587,23 +578,17 @@ public function sendUpdateEmail($notifyCustomer = true, $comment = '')
             'comment'  => $comment,
             'billing'  => $order->getBillingAddress(),
         ]);
-        $mailer->send();
 
-        return $this;
-    }
+        /** @var Mage_Core_Model_Email_Queue $emailQueue */
+        $emailQueue = Mage::getModel('core/email_queue');
+        $emailQueue->setEntityId($this->getId())
+            ->setEntityType(self::ENTITY)
+            ->setEventType(self::EMAIL_EVENT_NAME_UPDATE_SHIPMENT)
+            ->setIsForceCheck(true);
 
-    /**
-     * @param  string      $configPath
-     * @return array|false
-     */
-    protected function _getEmails($configPath)
-    {
-        $data = Mage::getStoreConfig($configPath, $this->getStoreId());
-        if (!empty($data)) {
-            return explode(',', $data);
-        }
+        $mailer->setQueue($emailQueue)->send();
 
-        return false;
+        return $this;
     }
 
     /**
diff --git a/app/code/core/Mage/Sales/Model/Order/Shipment/Comment.php b/app/code/core/Mage/Sales/Model/Order/Shipment/Comment.php
index 7ed9fbf0592..792691687a6 100644
--- a/app/code/core/Mage/Sales/Model/Order/Shipment/Comment.php
+++ b/app/code/core/Mage/Sales/Model/Order/Shipment/Comment.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * @copyright  For copyright and license information, read the COPYING.txt file.
  * @link       /COPYING.txt
@@ -14,19 +16,10 @@
  *
  * @method Mage_Sales_Model_Resource_Order_Shipment_Comment            _getResource()
  * @method Mage_Sales_Model_Resource_Order_Shipment_Comment_Collection getCollection()
- * @method string                                                      getComment()
- * @method int                                                         getIsCustomerNotified()
- * @method int                                                         getIsVisibleOnFront()
- * @method int                                                         getParentId()
  * @method Mage_Sales_Model_Resource_Order_Shipment_Comment            getResource()
  * @method Mage_Sales_Model_Resource_Order_Shipment_Comment_Collection getResourceCollection()
- * @method $this                                                       setComment(string $value)
- * @method $this                                                       setIsCustomerNotified(int $value)
- * @method $this                                                       setIsVisibleOnFront(int $value)
- * @method $this                                                       setParentId(int $value)
- * @method $this                                                       setStoreId(int $value)
  */
-class Mage_Sales_Model_Order_Shipment_Comment extends Mage_Sales_Model_Abstract
+class Mage_Sales_Model_Order_Shipment_Comment extends Mage_Sales_Model_Order_Comment_Abstract
 {
     /**
      * Shipment instance
diff --git a/app/code/core/Mage/Sales/Model/Resource/Order/Comment/Collection/Abstract.php b/app/code/core/Mage/Sales/Model/Resource/Order/Comment/Collection/Abstract.php
index 17b7c57f937..4ea9d3c9fd0 100644
--- a/app/code/core/Mage/Sales/Model/Resource/Order/Comment/Collection/Abstract.php
+++ b/app/code/core/Mage/Sales/Model/Resource/Order/Comment/Collection/Abstract.php
@@ -11,7 +11,7 @@
  * Flat sales order abstract comments collection, used as parent for: invoice, shipment, creditmemo
  *
  * @package    Mage_Sales
- * @template T of Mage_Core_Model_Abstract
+ * @template T of Mage_Sales_Model_Order_Comment_Abstract
  * @extends Mage_Sales_Model_Resource_Collection_Abstract<T>
  */
 abstract class Mage_Sales_Model_Resource_Order_Comment_Collection_Abstract extends Mage_Sales_Model_Resource_Collection_Abstract