I was suspicious to start because (1) From_ bore no resemblance to From:;
(2) the earliest Received: line was on best.com, which might make sense for
mail from carasso.com but not for mail from chaph.usc.edu; (3) the request
was addressed to an alias for a bunch of lists ("lists @
rather than to my list; and (4) the text asked to be added to "your list"
rather than giving the list's name.
Based on the alias and on the whois info Steve Portigal posted, apparently
carasso.com's ISP is best.com.