We would need to see the original message that came with the error report, in order to gain any real clues about what may be going on. A possible scenario is one of your subscribers has picked up a virus which has used your list-address in the From: field of the messages it generates, and your list/site is seeing various responses to some of that from places your list has never been, but where your infected subscriber has gone. I've actually seen traffic addressed to some of the lists here saying "you are not allowed to post" to lists on other sites we have no contact with - but sometimes the names are such that I can recognize why some of our subscribers would be subscribed there too.... hence both our lists and the other site's lists are in a common address book for viruses or spam engines to play with. In other words, the virus/spammer generated a message with a list here as the From: and a list there as the To: value. Your list might also have been found worthy of inclusion in one or another spammer address list somewhere, some of the lists here have gained this wretched honor. >>> [log in to unmask] 4/11/2006 9:13:23 PM >>> Hello LISTSERV, Within the last week, I've been getting reports from the system that some messages could not be delivered. But the undeliverable messages were FROM someone I've never heard of and it's clearly spam and I don't even know how my particular list is involved. Here's one of the error messages (to which the bogus message was attached): The enclosed message, found in the ZFW-TMU mailbox and shown under the spool ID 25704 in the system log, has been identified as a possible delivery error notice for the following reason: mail origin is listed in the "Filter=" list header keyword (or its default value for the ZFW-TMU list). At the same time I started getting these, I started getting monitor reports from the same list on subscribers who - well, they're NOT subscribed. Example: The following 2 subscribers are currently being monitored: Err First Last Address --- ----- ----- ------- 1 04/08 04/08 [log in to unmask] Last error: 5.1.1 Unspecified; usually "Bad destination mailbox address" 1 04/08 04/08 [log in to unmask] Last error: 5.0.0 X-Postfix; unknown user: "abhilasha" Again, neither of these addresses are subscribed to the list in question. Interesting but how do I stop this? -- Best regards, Tim