Thomas Spuhler:
Why would you use D_REJECT This would just tell the spam sender they have a valid address.
I find it generally a bad practice to discard messages¹. Users will learn, that messages may be delivered or not.Messages from real users will end up in a dark sinkhole from users point of view.
That's what I try to avoid.I always reject or deliver. That's a question of building reliable message systems.
Andreas ¹) yes, there are rare technical reasons...
