I had forgotten. Here's an explanation: https://help.returnpath.com/hc/en-us/articles/220568667-What-is-backscatter-#:~:text=Backscatter%20is%20auto%2Dgenerated

I had forgotten. Here's an explanation: https://help.returnpath.com/hc/en-us/articles/220568667-What-is-backscatter-#:~:text=Backscatter%20is%20auto%2Dgenerated%20email,the%20message%20cannot%20be%20delivered https://help.returnpath.com/hc/en-us/articles/220568667-What....