Karl Pearson wrote: > Bob Proulx wrote: > > Jeremy Morton wrote: > >> ...backscatter... > >> 'Your message to Gatewayav-discuss awaits moderator approval' > > > > The GNU Mailman mailing list software is a big offender in that area. > > I own a mailing list server. One of our policies are specifically about > "Challenge Servers" . . . We don't accept any. If someone hasn't > previously entered our server in so we don't see the responses, we > unsubscribe them without comment. Some might think that's harsh. I > don't.
I agree with your policy. Challenge Response backscatter is a bad thing. But that is a slightly different case from the backscatter case from Mailman. In this case Mailman at the mailing list server is the one generating the noise and not the client off on the internet. Mailman has a behavior that when mail is held for approval it will send a message back to the From: address informing them that their mail is waiting for approval. In concept this is the same problem as an MTA that sends status messages when mail is delayed by four hours. It thinks it is being helpful by informing you of the status. But the reality is that it is simply a spam source. It will respond to any forged From: address and so we end up receiving those from random Mailman servers all over the Internet. Additionally I have found that many people are confused by those status messages. Even when they correctly find the real sender they often simply confuse the non-technical user. It is possible to configure Mailman so that it doesn't send messages when they enter the hold queue. But I don't think it is the default. And so there are many instances of misconfigured servers on the network. Bob
