Magento 2 SMTP Extension prevents emails from going to spam. It sends emails through trusted SMTP servers instead of the default PHP mail function. The extension ensures proper authentication with SPF, DKIM, and TLS protocols. This helps email providers recognize messages as legitimate. It also maintains consistent sender details and logs outgoing emails. By using Magento 2 SMTP Extension, store owners can improve deliverability, reduce spam issues, and make sure their messages reach customers' inboxes reliably.