Informz sends a Bad Email writeback to Personify360 if a mailing cannot be sent to an email address due to it being malformed, having an invalid domain, or being a consecutive bouncer. The Activity Text in Personify360 includes the reason as to why the email was not delivered.
Signed, Sealed, Delivered
It's inevitable that some email addresses just won't allow you to send mailings to them. While it's hard to say good-bye, unsubscribing is really the best thing to do for your email sender reputation. Coordinate with your member/donor/customer service teams to come up with a process to reach out to those that haven't supplied current email address information to your organization. It's work, but it's good work that will help you and your organization.