In article <53a9c16c-163c-a18a-371a-f8aa8697af15@xxxxxxxxx> you write: >Question for ya on that Barry - do you think that MUA >and mail server implementers would actually bounce >messages as strictly as Martin's document might call >for? I'm not Barry but I can say that increasingly we do. We observe that spamware is badly written, and there are mechanical errors that are strong indicators that the sender is not someone you want to hear from. A common spamware error is "early talking", sending SMTP commands before the server's initial banner. If you wait a few seconds before sending the banner, and hang up on anyone who sends a command first, you'll lose a lot of spam at low cost. Another is greylisting, deliberately soft-failing a new sender and seeing if it retries, since spamware generally won't. There's another whole can of worms about what to do with mail that doesn't validate under SPF, DKIM, or DMARC but let's not go there now. R's, John
