I work in SMS sending, and every link in the chain has to reason about how they fail. If there is a failure, it is better that the message is dropped than that

I work in SMS sending, and every link in the chain has to reason about how they fail. If there is a failure, it is better that the message is dropped than that it gets resent duplicated. It would be a bad system indeed if a failure to write a log line (say) caused a retry loop that resent the message again and again...