An effective & appropriate promotional email campaign is an important part of any business. It’s no doubt that email is one of the most widely-used among the general population; therefore, reaching to promote via this communication channel has become an indispensable part of eCommerce.
However, on the default setting of Magento 2, unregistered emails will be automatically assigned to be sent via the default email server of the current hosting. This, as a result, will significantly decrease the reputation of your emails. The emails that you’ve dedicatedly designed will be marked as unreliable content & hence are likely to be sent directly to the customer’s spamming box or even rejected without standing a chance to appear on their notification.