I do understand how unsubscribe works in any email program and how it gets updated in Marketo each time any user prefers to be "unsubscribed".
That wasn't true earlier today though. 🙂
However, I have never faced any scenario where there is any issue with the domain being listed as spam that we are using and in this case I will take it with my team and decide regarding burning off the domain and think of some solution.
Every email you send now with a blocked domain is not respecting other instances. So please do not send anything until you have requested removal from the DBL. If you are successfully removed then you can continue to use the domain.