SMTP AUTH ‘needs’ that the sender is approved to make use of the server to send emails. It causes it to be more durable to impersonate real buyers, shielding them from spoofers and spammers. This can be a buffer where the emails are stored just before they strike the endpoint. https://becketttcebz.tusblogos.com/26519529/the-fact-about-linux-server-expert-that-no-one-is-suggesting