Yes, but the "bounce message" comes to the sender from their own mail system, saying "could not deliver".
This is important, because the receiving system doesn't have a guaranteed way of reaching the sender - modern spam typically fakes the "From:" and <return-path> fields - so well-run systems nowadays never try to do so for fear of generating what's referred to as email backscatter spam.
Comments
Yes, but the "bounce message" comes to the sender from their own mail system, saying "could not deliver".
This is important, because the receiving system doesn't have a guaranteed way of reaching the sender - modern spam typically fakes the "From:" and <return-path> fields - so well-run systems nowadays never try to do so for fear of generating what's referred to as email backscatter spam.