Re: All spam filters fail in comparison...
> % % ... to TMDA. It's not a filter,
> % a
> % % whitelist/blacklist based
> % % challenge/response system.
> % Argh....
> % This is the worst and most rude
> % solution.
> % I do not want to have to ack your TDMA
> % mails, I automatically
> % block you from all my mail servers as
> % soon as I receive a confirmation mail,
> When used properly, it's very effective.
> This includes list subscriptions like
> your mailman newsletters. If you just
> throw it up and don't take care of it by
> actively (and proactively) managing your
> whitelist, it's useless.
> Also, you'd better get used to those
> confirmations. Until some major, radical
> change is enacted with a protocol (like
> SMTP) to combat spam, these
> challenge/response systems are going to
> be more and more commonplace.
> TMDA responds to the "return-path"
> header address. I personally use ezmlm
> to manage my lists, and the return-path
> header automatically removes these
> persons with the "ack" emails coming
> back to the system.
> -- Gun
Sorry Gun, after a couple of painful "challenge|response|fail" message sequences, I tend to agree with Mark. I have not had the pleasure of encountering a user who has made a good use of a challenge|response system.
If I ever get an e-mail challenge from someone I know personally, I will advise them the next time I see them that they need to add me to their whitelist themselves, I will not play the challenge|response game. If I ever again encounter a challenge from someone who has given me their e-mail (or rather given an organization I am a part of, with the understanding that someone will be sending them e-mail) I will block that e-mail address at my server. If I get a challenge in response to my responding to a message they sent, it tells me that they have their filter set up incorrectly, and I will treat that e-mail address the same way as if I received a bounce from them.