[Exim] where/how to place authenticated sender info

hi,

this is mainly a request for advice, as technically i can do myself
what this message is about :)

i decided to re-introduce my config snippet that, when a message is
relayed using some form of authentication, places tha authenticated
sender somewhere in the headers.

currently the config looks like:

received_header_text = "Received: \
[snip]
id ${message_id}\
${if def:authenticated_id { (authenticated sender: \
${md5:${authenticated_id}${message_id}ASMTP_HEADER_SECRET})}}\
[snip]

first question: which is 'better', using "if def:authenticated_id" or
using "if eq{received_protocol}{asmtp}" ? both forms produces the same
result, as far as i know now.

second question: shall i be putting the auth sender information in the
received headers as above, or introduce a (say)
X-Authenticated-Sender: header, and put it there ? the main pro is
the amount of work required (as adding a new X-header should be done
in almost all of the transports), no cons i can think of.

thanks,


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