Mailing List Failure Modes

We had an O’Reilly editors email alias, which grew from editors to almost everyone in the company. At that point we started a radar mailing list for just the “emerging technology” folks. That list has grown as we’ve added more bloggers to Radar and as more people within the company are interested. Recently we added a dealflow alias because there were people on Radar who aren’t covered by OATV’s NDAs and frieNDAs. Today Marc Hedlund made a perspicacious comment on the Radar mailing list:

O’Reilly mailing lists tend to grow until they include
everyone, at which point a new list is created. Please let me
know if any of our competitors join. :)

Does your company face or project mailing list bloat? Is it crazy to ask whether you have found any strategies that work? The question does rather invite the response “just don’t add more people to the list”, but that seems overly simple—there are always people with legitimate desire, interest, and relevance. I remember reading (though can’t find an URL to cite for it) that Ray Ozzie’s policy at Groove was to forbid more than n addresses on CC: lists, where n was something like 3 or 5. Marc pointed me to hottubbing as one system, but I’d love to know what other groups have done to manage the Borgian tendencies of mailing lists.