> On my incoming email, Sender is never tech-embed@netbsd.org, but
> always the name and email of the person who sent it, in the case of
> your post, abs@absd.org.  Thus can't filter it.

This is almost certainly something broken with your mail setup.  Your
message, as it arrived here, included a header

> Sender: tech-embed-owner@NetBSD.org

Alternatively, perhaps abs sent to you as well as the list and some
kind of de-duping setup dropped the list copy, perhaps because it
arrived later?  Then the version you'd see would be the one that didn't
pass through the list.

There's also the envelope-from, which you are supposed to be able to
find in a delivered message in the form of a Return-Path: header.
("Supposed to be able to" here = "this is what the spec calls for".)

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