I spoke with one systems administrator who said that my messages were
being received with PRECEDENCE=NORMAL, and the sysadmin uses that to
gauge who gets an auto-responder.
So despite all the other indicators, such as having List- headers,
coming from an envelope sender address that includes the string "owner"
or "request" or "bounce" or "errors" or "admin," and most significantly
the absence of the user's address from the To: line, the autoresponder
was still allowed to yak away, and the administrator's excuse was that
[s]he has decided unilaterally that only one criterion counts?
I sent my stuff out with Precedence: list, so if that had happened on
any of my lists I would never have known. But if I found out I'd have
certainly given that admin the URL to Jeff's rant.