Looking for a good explanation of why people should use "reply to" to avoid breaking mailing lists threads when replying.
I didn't find what I was looking for, but here are some good "mailing lists netiquette" links:

• Apache Jakarta Project - mailing lists guildelines
• Howard Rheingold - The Art of Hosting Good Conversations Online

Does anyone have a good explanation or reference about the "reply-to" thing? I'd like to add it here.

Update: after questioning a mailing list user who sends messages without the required in-reply-to header, it seems like some versions of the Outlook mail client do not handle this header properly.
Cool. Now I have two nicknames for Outlook, virus pipeline and thread killer :-)