Too bad they did not differentiate between Create and Overwrite (as far as I can tell) as that is a an important difference (I need to solve scenarios where idempotency is needed - more than 1 worker may create exact same email message due to fault tolerance design, but at least AND at most 1 email should be sent to customer. I was hoping that the s3 filename/key would be the unique identifier and if there was separate notification for overwrite than from create, email could be sent only for create event only.)