The main purpose of Magento 2 Custom SMTP Extension is to make your email-sending process secure and efficient. With the help of this extension, you can customize the email server settings of your Magento 2 store, which improves the email delivery rate. Many times emails sent from the store go to the spam folder, due to which important information does not reach the customers. This extension helps in managing your SMTP server and delivering emails directly to the inbox so that your customers can receive every important update on time.