David Cantrell wrote: > On Tue, Aug 11, 2009 at 06:30:39PM -0500, Exim wrote: > >> I just had a client ask for something I haven't done. He wants emails from >> unknown users to be sent back with a "are you human" request they must >> respond to correctly. If they do, then they will be automatically added to >> a list of valid senders. >> >> (and no I don't want to do this, but sometimes you have to do what the >> client demands, rather than what is really best for them). > > Yes, you do. But that doesn't stop you from trying to dissuade them! > My argument against it is thus: > > Spammers rarely send email with legitimate From: headers - when the > address exists at all, it's almost always that of some poor innocent. > So, when you send the "are you real?" email, you're either annoying > some legitimate email sender (and potentially losing their business) or > you're sending it to someone who has never heard of you. In that latter > case they're likely to say "yes!" just to piss you off and let the spam > through. But more importantly, challenge/response IS SPAM, because it > is unsolicited bulk email. No-one solicits it - your legitimate > correspondents never asked for it, and obviously the poor innocents > you're subjecting to it didn't either. And it's bulk, because it is > sent with substantively the same content to every recipient without > regard for whether the recipient is me or the king of the moon. >
Not mentionning that your server will ultimately get blacklisted at some point, even automatically if you send such an automated reply to a spamtrap.
smime.p7s
Description: S/MIME Cryptographic Signature
-- ## List details at http://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
