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Backspin Feedback for "SBC makes DSL, er, exciting" (3/21/05)
By Gearhead, NetworkWorld.com, 03/26/05
Regarding the Backspin Column "SBC makes DSL, er, exciting" we received the following from a "robwfutura" (no name supplied so e-mail address less domain used) on Friday, March 25, 2005 2:35 PM:
This guy really needs a clue. He has absolutely no idea how the spam organizations are working. He needs to pull his head out of the clouds and do a little research. What he'll find is that "this ridiculous and ineffective program" combined with other ISP's doing the EXACT same thing, has pushed a decrease in spam that is somewhere between 15%-25% depending on who's figures you believe. I will definitely start ignoring anything quoting this source.
Mark Gibbs's response:
Wow. That's a remarkable amount of hostility over a subject that you wouldn't think could get someone so riled up. From the research I've done I have yet to find a definitive answer as to the effect that port 25 blocking is having on spam reduction. In fact I have found no evidence yet for any drop in the overall spam percentage and if you believe the MessageLabs statistics (click on the "spam" tab) the overall level is still trending (albeit slowly) upwards! If robwfutura would care to reply with where he found his figures of 15 to 25 percent spam reduction I'd be very interested.
I suspect that Port 25 blocking seemed to make sense as a way of blocking zombies (see MessageLabs commentary) but the contribution of zombies to spam appears to be dropping for reasons unrelated to port 25 blocking.
Even the zombies are getting around port 25 blocking! Again according the MessageLabs: "In recent months, spammers have been changing tactics in order to side-step anti-spam counter-measures being introduced by ISPs, such as SMTP (TCP port 25) traffic blocking. For example, Send-Safe is now able to route spam email by redirecting the email traffic from the spam trojans via each compromised PC’s ISP email server, rather than to attempt delivery itself."
Blocking zombies doesn't cure the problem, it just pushes their evolution! What you get with port 25 blocking is better zombies!
What I have found is a huge amount of commentary from really, really annoyed end users whose ISPs failed to inform them of a port 25 blocking policy before implementing the policy. Do some research and see how poorly many ISPs have served their customers over this issue.
So, despite robwfutura's assertions and anger I see little evidence that port 25 blocking has been or will be successful in the bigger picture of solving the spam problem and my description of the tactic as a "ridiculous and ineffective program" still stands.
Thanks for writing.
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Comments
Think of the impact ISPs could have on SPAM and all other hacking activity if they dropped customers completely? See the customer isn't the problem - they're the source of revenue. ISPs need to deal with this issue with the assistance of, not to the detriment of - their customers. Alientating customers by implementing serious changes without notification builds anomosity and distrust.
Posted by: Greg on March 28, 2005 03:16 PM
