being able to see whose emails have suddenly gotten blocked after months of them being delivered so we can tell when our members aren't getting their emails. This random blocking happens ALL THE TIME but the system still shows them as being delivered.

I've had member's emails blocked months after they joined and have received emails, but it still show the emails as being delivered. IT IS CRITICAL to know if a member's email has been blocked. How can I run a business when my members emails are randomly getting blocked and I don't even know about it and your system tells me they are being delivered?