DISQUS

danielmiessler.com | grep understanding: The Worst Anti-Spam Technique Ever: “Bouncing” Spam Messages

  • Carl M · 3 years ago
    He's not replying to the message, he's "bouncing" it back ... basically the system sends back the same "This is an invalid address" message that gets sent when mail is sent to an invalid address.

    This is not to say that this is a good idea. But it's not quite as stupid as just replying to the spammer to tell him that you'd really rather that he didn't send you advertisements for v1aG ra.
  • Arik · 3 years ago
    Another technique which I personally don't like but is being used:

    First attempt from an IP address, reply with a 4xy SMTP error code (to those not versed in SMTP, it means 'temporary problem, please try later'.

    Second attempt from the same IP address for the same recipient: process normally.

    The idea is that spamming software doesn't manage a 'deferred' queue and would just give up on messages that get a transient (4xy) error message.

    The downside is that legit messages take a long time to get there, some 5 minutes at least.

    I'm not sure how well that works.

    -- Arik