![[info]](http://p-stat.livejournal.com/img/userinfo.gif){kind=small}
This is Not a Brain Surgery
Nov. 3rd, 2007
06:54 pm - GMail as spam filter, using IMAP
One of non-obvious implications of Gmail offering IMAP interface, is that now you can easily access from outside your SPAM folder. It might sound like not such a big deal, but it opens access to Gmail spam filtering technology, which seems to be very good.
One obvious use is to use Gmail account as honey pot, and train your local spam filter using corpus of spam, caught by Gmail. I can see a cron task, fetching new spam from Gmail via IMAP and training spamassassin with it via 'sa-learn' command.
Another use would be to build a plugin for spamassassin, which sends a copy of each new message to gmail account with SMTP, when waits for it to appear either in INBOX or in SPAM folder. Thus, one could use Gmail as a spam filter.
Oct. 3rd, 2007
11:43 am - hashcash, Outlook Postmark
Without much fanfare Microsoft have included in OutLook 2007 a Postmark feature which is using "Math Puzzle" for SPAM control:
"A new Outlook E-mail Postmark feature aims to make it easier for other Outlook 2007 users to receive legitimate messages that might otherwise be classified as spam. When a user sends a “spammy” message, Outlook performs the calculations necessary to solve a simple computational puzzle and adds information about the puzzle and the solution to the SMTP message header. Because that computation takes only a little time for one message or a few messages but would take a very long time for a spammer sending millions of messages, the presence of an Outlook E-mail Postmark in the message header is a strong indication that the message isn’t spam."[1]
This is basically an implementation of old good HashCash idea. I think this is great that they are doing this. This is one of few ways which allows to combat zombie computers sending spam email. I wish this implementation become more mainstream in other mail clients.
However, there are several problems with Microsoft approach. The first is that a Postmark feature is switched off my default [2]. The second is that according to some reports[3], Microsoft owns a patent on this technology, which could stop its adoption by other email software vendors. I also have not found a clear technical specficaiton of Postmark implementation, which could be used, for example, to add postmark checking to SpamAssassin.
Oct. 31st, 2005
11:53 pm - spam dictionary attacks and sendmail
I am in constant fight with spam. The reason is that I believe in single, universal, life-long email address and refuse to hide or change my primary email address which I am using for 10 years already. I think we should all fight spammers, not just passively suffer. I consider Internet to be my second home, and I remember it is being free of this plague and I hope it would be again, some day.
( So, today I was again fine-tuning my Sendmail (with the help from my networking wizard friend) and would like to share couple of spam-fighting sendmail configuration tricks. )