Re: Email Invalid - Opened An Email After Going Invalid?
Since you won't have a timestamp that you can easily access on the email invalid data change, you should set this as a Triggered Smart Campaign to be a point-in-time update on that data value for anyone who qualifies.
Flow action would be the Data Vaue Change to make Email Invalid = False.
This should catch anyone...I'd keep a close eye on this, though, to make sure it's not inadvertently creating a strain on the system. It shouldn't, but always best to watch new campaigns closely anytime you launch them!