The Boston Diaries

The ongoing saga of a programmer who doesn't live in Boston, nor does he even like Boston, but yet named his weblog/journal “The Boston Diaries.”

Go figure.

Thursday, August 16, 2007

Notes on an anti-spam system

At the weekly meeting the other day, Smirk asked me to look into some alternative anti-spam measures, since more and more spam is making it past the spam firewall. I mentioned the success of greylisting and he told me to look into it.

I've currently downloaded several packages for both Sendmail (what we use at The Office) and Postfix (what I personally use) and there's better support for greylisting now than there was three years ago, but I'm rather puzzled that all the implementations so far use some form of database backend to keep track of all the requests (tumgreyspf uses the filesystem, but as Mark likes to point out, that's a form of database) when one could just as easily keep track of the requests in memory.

It's not like we're stuck with 256M of RAM these days. Even on my Mac mini, the resident set size of Firefox is 16M and I figure you could store about 65,000 requests (which would be swept clean every hour anyway) in 16M.

So my plan is to write some greylist software that keeps everything in memory, so it should be fast, with no worries about resource exhaustion. The protocol used in Postfix is easy, and I can cannibalize code from two previous daemons I wrote to get up and running rather quickly.


Hey, they have a hard enough time predicting the weather ten days from now. What makes you think they can get it right a century from now?

D.C. resident John Lockwood was conducting research at the Library of Congress and came across an intriguing Page 2 headline in the Nov. 2, XXXX edition of The Washington Post: “Arctic Ocean Getting Warm; Seals Vanish and Icebergs Melt.”

Via Instapundit, Bef ore Gore

The article in question was written before Al Gore became famous for Global Warming. In fact, the article in question was written before Al Gore was even Vice- President. The kicker?

It was dated November 2, 1922!

Sad to say, but the East Coast is still here.

Obligatory Picture

[The future's so bright, I gotta wear shades]

Obligatory Contact Info

Obligatory Feeds

Obligatory Links

Obligatory Miscellaneous

You have my permission to link freely to any entry here. Go ahead, I won't bite. I promise.

The dates are the permanent links to that day's entries (or entry, if there is only one entry). The titles are the permanent links to that entry only. The format for the links are simple: Start with the base link for this site: https://boston.conman.org/, then add the date you are interested in, say 2000/08/01, so that would make the final URL:

https://boston.conman.org/2000/08/01

You can also specify the entire month by leaving off the day portion. You can even select an arbitrary portion of time.

You may also note subtle shading of the links and that's intentional: the “closer” the link is (relative to the page) the “brighter” it appears. It's an experiment in using color shading to denote the distance a link is from here. If you don't notice it, don't worry; it's not all that important.

It is assumed that every brand name, slogan, corporate name, symbol, design element, et cetera mentioned in these pages is a protected and/or trademarked entity, the sole property of its owner(s), and acknowledgement of this status is implied.

Copyright © 1999-2024 by Sean Conner. All Rights Reserved.