[EXIM] Sender: and From line rewriting

For every message that we rewrite a (header) From line for we would like
to add a (header) Sender line with the original value unless there already
was a Sender line (which we then won't tamper with).

I actually think that this should be normal behaviour for all From line
rewriting. I'm I wrong? How can I do this with exim?

-j
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Jeffrey Goldberg                +44 (0)1234 750 111 x 2826
 Cranfield Computer Centre      FAX         751 814
 J.Goldberg@???     http://WWW.Cranfield.ac.uk/public/cc/cc047/
Relativism is the triumph of authority over truth, convention over justice.

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