Invalid email address in Taguchi means that our bounce classification system has determined that an email address should no longer receive emails due to the number of bounces received while attempting to deliver. Taguchi makes multiple delivery attempts to email addresses before flagging them as invalid, and a final determination occurs after considering the number of bounces, the type of bounces, the number of successful deliveries, the amount of time the address has been in our systems, and the history of interaction from that address.

To find out more about our bounce classification system, please see What Is An Email Bounce?