Well, it wasn't anything that I did different, cus I didn't do anything different. Maybe those "Message Delivery Delay" messages were something different for Lunarpages over the past month and a half, but, that would seem to be a problem with their equipment.
Lunarpages' latest response is:
"We believe that this blocking was placed by our system due to a misconfiguration. We have now ensured that our smarthost ip wont be blocked again by the same server due to multiple connections and you wont be experiencing the same issue again in the future."
OK, I do not have any experience as a web host, but, shouldn't a web host/domain/server have the ability to handle multiple connections without deciding that the domain/server should be (automatically) blocked? What is involved in the descision-making process where a technician is confronted with the question "should your own smarthost IP be blocked if your own servers are generating multiple connections?" and then decides "yeah, let's completely stop our client's email without any type of notification because of something we don't want to investigate right now, although we risk getting sued for violation of user agreement and loss of business". I would consider my domain to be a very low-usage client, but, I used Plesk (provided by Lunarpages) to schedule two tasks to run at the same time. If that is something that Lunarpages servers can't or don't want to handle, why does Lunarpages allow Plesk to schedule such a "problem"?
The overriding theme with the vast vast majority of my support issues with Lunarpages seems to be very simple: I have done nothing different to my domain for months, all of the sudden something stops working, I receive no notification of a functionality being changed or stopped, I contact support with an outline of the problem, support is immediately able to identify and correct the problem (sometimes after questioning/accusing me of having made a change), the "cause" seems to be something that Lunarpages changed without notification, and, Lunarpages does not provide any explanation as to why they made the change, why they did not notify me of the change, or, any type of plan of how to avoid these types of problems in the future. They always seem to end their communications with "Thank you for your patience and understanding while dealing with this issue", but, I don't recall them EVER apologizing for a mistake that they made.
Is this the way that most web hosts treat their clients?