Slashdot Mirror
I am the Most Spammed Person in the World
jefp writes "In November 2004, Microsoft's second-in-command Steve Ballmer made some headlines by mentioning that Chairman Bill Gates was getting four million spams per day. At the time, I was dealing with a little spam problem of my own - I was getting around a million spams per day. I found it a little comforting that my problem wasn't quite as bad as Bill's. However, a couple of weeks later Ballmer corrected himself, saying he mis-remembered the stat and Gates actually gets four million per year.
This means I was getting one hundred times as much spam as Bill Gates.
I've written a tutorial explaining why I get so much crapmail and how I deal with it."
he just went from 1 million a day to about 1.3 million a day.
for Spamalot
you don't post your email address to farmgirls.com!
Give a man a fish and he'll eat for a day. Teach him to fish and he'll wipe out the species.
...but not with one slashdotting.
He's really just using Slashdot to break his server farm so he won't have to get spam anymore.
You can only be young once, but you can be immature forever.
I'm pretty sure whoever runs nowhere.com can give you a run for your money in the most spam inbound. Although a lot of those are probably from organizations thinking they're sending to legit opt-in requests.
Keep my web service running too, since it's on the same machine.
/. front page?
You try to do this by submiting a story to
Ubuntu is an African word meaning 'I can't configure Debian'
Just yesterday I enabled Greylisting in OpenBSD spamd, and today I got 6 spams, compared with my usual 150. (per day).
It's easy to set up and works with your existing mail server. OUr mail server is qmail on red hat, but openbsd just ahppily redirects the legit (what it suspects might be legit rather) to the mail server. The load has dramatically decreaed on the mail server.
/* oops I accidentally made a comment, sorry */
Your name in the posting is a link that resolves directly to your email address.
Don't know what you're doing right now to reduce the spam, but maybe putting your email address on the front page of Slashdot is a step in the wrong direction.
There are 2 kinds of people in this world. Those that can keep their train of thought,
Just to alleviate some of his bandwidth, I have mirrored the mail_filtering pages. Looks like it's all there. Let me know if you want me to take it down.
"To err is human, to forgive is simply not my policy." --root
I dont get nearly as much spam as that, but even a few hundred a day is pretty irritating. My solution is to delete all email as soon as I get it.
I figure if its important I'll get a phone call.
air and light and time and space
I wonder if Bill changes email addresses as much as I install security patches. Karma's a bitch.
but now he's the most slashdotted person in the world
:D
Hmmm...
* "World's biggest hacker"
* "World's Fastest Inkjet Printer"
And what we have here? The "most spammed person in the world" becomes "the most slashdotted person in the world" who used "the most over-used headline cliché in the world".
Ladies and Gentlemen, we have a winner!
That is impressive, but I imagine that any catch-all email addresses at foo.com or test.com might beat even that.
concrete5: a cms made for marketing, but strong enough for geeks.
Hmm... the article was submitted by jefp, and from the website: © 2005 by Jef Poskanzer. You don't suppose they could be the same person, hmm?
The site seems to be slowing down, but the coral cache is going strong.
I like his slam on qmail. Does djb ever address such concerns?
-mkb
thanks for the plug xtracto, I created and maintain dodgeit.com :-)
We were getting well over 1 million spams a day before we started using DNS blacklists. I'm stunned that the story author is weathering the storm with sendmail. I never could configure that beast. Dodgeit is a postfix shop.
slashsearch.org - slashdot search. powered by google.
I think the line
kinda gave that away already.
If you disagree, post your argument. (-1, Overrated) isn't your personal censorship tool for views you don't like.
Mail Filtering
Or, how to block a few million spams per day without breaking a sweat.
© 2005 by Jef Poskanzer.
Introduction
In November 2004, Microsoft's second-in-command Steve Ballmer made some headlines by mentioning that Chairman Bill Gates was getting four million spams per day. At the time, I was dealing with a little spam problem of my own - I was getting around a million spams per day. I found it a little comforting that my problem wasn't quite as bad as Bill's. However, a couple of weeks later Ballmer corrected himself, saying he mis-remembered the stat and Gates actually gets four million per year.
This means I was getting one hundred times as much spam as Bill Gates.
Nevertheless, after filtering we both get about the same amount: around ten spams per day in our inboxes. Ballmer says that Microsoft has an entire department dedicated to protecting their mailboxes from spam. At ACME Labs there's just one guy, one server, and a T1 line. And yet my filters are a hundred times as effective as Microsoft's. How do I do it?
These pages will show you how, and help you deploy similar filters on your own system.
Goals
What am I trying to do here?
Results
For those who like to read the end of a novel first, here are some overall stats showing how the filters are performing.
Environment
This is all based on a Unix system running sendmail. If you're not using Unix, or you're using a different Unix-based mail system, most of the specific advice here will not help you. You may still find some value in the general ideas.
Sendmail Config
The first layer of spam defense is sendmail itself, because that's the first piece of software to touch each message. Sendmail has a number of different config options that can help you block spam and keep your machine stable.
greet_pause
As of version 8.13, sendmail added an anti-spam feature called "greet_pause". It is both simple and clever.
In a normal SMTP transaction, first the client connects, then the server sends back a "220" greeting message, then the client sends its HELO command. Some spam programs, however, don't wait for the greeting message. They just send their commands immediately without listening.
The greet_pause feature detects this misbehavior by pausing briefly before sending out the "220" greeting message. If any commands arrive during that pause, then the connection is marked bad and anything coming over it is ignored.
This one is interesting because it actually cuts down on the number of spam attempts, not just the spam deliveries. I figure when the spammers hit the pause they are somehow getting stuck. I'll have a graph of this later - before I enabled greet_pause, I was getting a couple million spam attempts per day; after, only 600,000.
To enable the feature, you need to make two changes. First, in your sendmail.mc file:
You probably already have access_db defined; it just needs to appear somewhere prior to greet_pause. The number is how many milliseconds to pause; 5000 = five seconds. Then in your access file you should add this:
The second change prevents the pause from applying
so I sent him an email asking for the text
This guy's SMTP server:Pipelining is turned on for untrusted hosts. Nice.
Either way, a good portion of the spam hitting my system never even makes it to EHLO/HELO time because if there's any sort of resolution problems with the dns/rdns or if the hostname contains the IP address in it (RFC violation) I delay the connection 20 seonds before the greeting. RFC states clients WILL NOT send data unless asked to do so, except for pipelining which is not advertised for untrusted hosts. When the MTA sees a bunch of incoming crap, it drops the connection because they violated the RFC rules for handshaking (clients MUST wait for the greeting). This does not affect legit MTAs with temporary problems.
I go through a whole bunch of other checks even before DATA time, delaying at each step if there's a problem. 90% of the spam/viruses never even make it to scanning for spam/viruses because they violate something before that and the connection get drops (or they drop it from waiting). Once again, delaying 20 seconds does NOT affect legit MTAs.
Big writeup on SPAM filtering
My MTA
In fact his Webserver still runs perfectly. Why do I know? Because I am reading his article. Slashdottings occur when webservers use more RAM than the system has. Kernel swaps, webserver allocates some more memory, tilt. So the obvious solution is to configure your webserver not to. :) I guess this is what he did. All incoming connects get queued by the kernel and handed over to the webserver if a slot gets available. It gets terribly slow (I can tell!), but if the user has a high timeout-value (of a minute or 2) then no error will occur at his end either.
:)
Very reliable tech I guess.
Meme of the day: I browse "Disable Sigs: Checked". So should you.
Laws do not persuade just because they threaten. --Seneca
I have had the same address since 1989, long before there WAS a spam problem. My email address was all over Usenet when Cantor and Seigel sent out their first spame, which means it's all over Google Groups. The horse is so far out of the barn its grandchildren are headed for the glue factory.
In 2000, the last time I added it all up, I was getting 300M a month *after* applying blacklists. At this point my mailserver is blocking several countries and ISPs, using multiple blacklists, and running some custom greylist software I wrote myself (for qmail... sorry, Jef), and my local mail client's only seeing 20-30 spams a day out of the hundreds of thousands (maybe as many as a million, it's too depressing to keep track) of delivery attempts that show up in my logs.
If you don't mind changing your email address now and then, more power to you, but I'm damned if I'll give the bastards the satisfaction.
A billion MIPS for defence, but not a byte for tribute!
Someone deletes all your thoughts as soon as you get them?
Singularity: a belief in the "God" idea with the "demiurge" relation inverted.
Hardware info here. It's a 3.2 GHz P4. I was struggling along on a 450 MHz box until only a year ago, but finally had to upgrade.
Maybe someone should create a blacklist blacklist?
cpeterso