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I'm afraid I don't find this to be a credible example. Sieve is
intended to be a language used in or around delivery time so users
can exercise some control over delivery processing. It is not
intended to be a general purpose message alteration facility.
It isn't? The whitepaper mentions not only final delivery uses, but also
periodic sweeps through a message store for administrative purposes
(aka cron jobs) as well as client-side filtering.
This was for filtering and redirection purposes, not for message alteration.
Esp. the editheader draft is one that is mandatory for client-side
filtering, b/c many clients provide that functionality now and it is
used where offered.
I'd even welcome a shell-out (execute_command/pipe_trough) extension,
even if it was never ever implemented on a server (and shouldn't), but
only in clients and local tools (like GNU mailutils' sieve).
I object in the strongest possible terms to this.
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