> I think the better approach here is to say that SNI logging adds to the
> information about the message's origins and history, and the same
> considerations as to whether or not to include things like server IPs also
> apply to SNI information.
Seems reasonable. In the usual case that you can tell who the recipient
of the message was, does the MX name or SNI or ESNI tell you anything of
interest that you didn't already know (other than that the client does
SNI?) I'm having trouble thinking of a plausible case.
The case that comes to mind is some sort of alias or list the message passed
through. It might be smart enough to edit the other stuff out of the Received:
field but not the SNI information.
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