When is [Time to be received] property of msmq message evaluated? -

When I send a message and set the TTBR property on the message: QueuedMessage.TimeToBeReceived = TimeSpan.FromSeconds (10);

When has this asset been evaluated and deleted messages have been deleted?

When or how the asset is evaluated, it is possibly deliberate. By doing so, Microsoft will keep its options open. When and how they want to evaluate the property at any time, they are free to change.

For some examples, the description says:

In each hop, message quowing will reduce the amount of time remaining from the value of PROPID_M_TIME_TO_BE_RECEIVED to the applicable computer , When this message sends to the next computer, where a new timer set.

But we probably should not read a lot of it in the phrase "... where a new timer is set." Some other non-timer related codes can be short stories and not signs of becoming a real timer.