I've never been on a mailing list where a good standard of behavior was enforced, and I'm still incensed by the laziness of just hitting "reply" when providing feedback. I will say that multiple part works just seem to be irritating in general when sent over listserve. My ideal would be a set of links to the various parts, sent in one email. The bomb-style dropping of seven parts of one fic into my email inbox drives me a little batty.