> Aliasing via virtual(5) is brutally efficient. No content modification,
> just message routing, so the header is not added.
>
> To add an X-Original-Recipient header, messages to multiple recipients
> have to be split into one copy per-recipient since the header you want
> is recipient-specific.
>
> Since the queue file contains a single copy of the message for all
> recipients, such rewriting *cannot* happen on input, it can only happen on
> output via a delivery agent that is processing a single recipient. This
> means you need a custom transport for this destination that processes
> mail one recipient at a time and prepends the header.
>
> This can be done via an external program via pipe(8) or by modifying the
> source code of the smtp(8) delivery agent so that the header is added when
> a suitable boolean flag is set and the message has exactly one recipient.
>
> The pipe(8) approach would then re-submit the mail for outbound delivery
> to a different Postfix instance to avoid loops.
>
> --
> Viktor.
Thanks again Viktor.
It sounds a bit more in depth than I was hoping for. Given the _only_ function
for this alias is to forward to one address, would it be possible to do a
simpler approach?
Regards, adam
