Your server is basically a special kind of relay. Your ML software must preserve the headers of the source email the same as any other relay. If your software trashes the headers, then you will continue to be victimized by spammers because you are effectively anonymizing their email - just what they want.
See the relay section at Open Relay Servers, on correct relay behaviour. Also, I have created a special set of FAQs for mailing list administrators (in this section of the FAQ). It includes info on how to reduce spam complaints and handle the ones you do get gracefully.
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I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.