There is action "ResumeSubscription" in EventDestination, how is the event suspended? I don't find the correspoding action. Does it depend on the "DeliveryRetryPolicy"? If the "DeliveryRetryPolicy" is "SuspendRetries", the event delivery is suspended after retries, and you can call the "ResumeSubscription" once the receiver is ready again.
Yes, a subscription could be suspended / disabled for a number of reasons, which you're correct is not exposed in the EventDestination - this was noted recently and something we need to address. We'd expect the Status/State property to show a "Disabled" state in this case, and yes, the ResumeSubscription action is for exactly that purpose.
You're correct that we don't have an Action defined to "SuspendSubscription" - I'll take that feedback as an issue to discuss.