My question wasn't actually about "the list" that reports the error, but the "subscriber address" in the problem report - is it ALWAYS Steve10.... every time? If it is the same, how many common subscribers do the various lists share where you've seen this problem? But I think the simpler solution is what others have mentioned, turn on Auto-delete and set the Probe() value very small, like 3 or less, for a week or two - it should weed out the problem for you (very soon if the list has at least one message a day going through it). >>> [log in to unmask] 04/20/01 07:00PM >>> Thanks for the ideas. Here's the answers: 1] Chris: the list always has been Subscription = Owner, and I have never added anyone with the suspect address. 2] Kevin: this is the latest occurrence. It happens mostly with this list, but also with other closed lists. What would constitute a clue? Any message from that address? 3] Rich: There's no one named Steve on the list, and mostly we use our yorku address or if not, then a cable connection - never msn. But I'm inquiring from an Esteve, though I doubt it. Thanks, Michael