I subscribe to a number of Rootsweb groups and I know they have been having a lot of trouble with one or two ISPs, particularly AOL and Big Pond(?) in Australia. There have been protracted negotiations between Rootsweb and AOL, and it seems to clear up for a while, and then AOLs software decides Rootsweb is a spammer again, and the mailing lists fill up with "I'm not getting any messages" messages.