1. Underground Forum

    Email marketing Mail bounces

    Common mail bounces and their description Hard bounce The response from the remote server was: 550 5.7.1 No such user! 1683454980-0NPfrE8P9Cg0-eRlBSO3h Hard Bounce - Indicates a permanent reason why the email could not be delivered. Causes for a hard bounce: The recipient's email address does...