NotifySender
Magento\Sales\Model\Order\Email\NotifySender
What it does
This abstract class serves as a base for sending notification emails related to sales orders in Magento 2.
Developers extend this class when creating custom email senders for order-related events (like order confirmations, shipments, invoices).
It handles the logic for checking if emails are enabled, preparing templates, and conditionally sending emails to customers or copying them based on configuration settings.