I'm using Mail in Tiger. Thanks for responding. I did learn (here at macnn) about the ability to delete individual messages on the server, but as someone who gets 30-50 spam messages a day, having them deleted from the server when I delete them locally saves me from that hassle on my other computers. The spam filter in Mail catches most of them, so it isn't an issue when I'm sitting at my Macs, but if I pull mail from a different machine, or from the ISP's Web mail, I would prefer to have deleted them the first time I saw them.
John