Yan Pritzker photographer, entrepreneur, software engineer, musician, skier

Shame on you Hotmail..one of five messages in junk is not junk!

Posted 10 February 2007 @ 6pm | Tagged thoughts

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I’ve been trying to figure out why hotmail keeps labeling our messages from Planypus as junk. Most other services let them through (gmail, yahoo), and running them through spam asassin gives us a very low spam-score. So i did some research and came across this article, albeit from one year ago, indicated that gmail’s false-positive spam rate at that point (that is, the percent of messages that get labeled as spam but are actually valid) is about 3%, while hotmail’s is 20%! And what’s more interesting, the average in europe is 0.075%, while america is at over 3% because of services like compuserve and hotmail which just don’t give enough of a shit about their users to fix this problem. It doesn’t take a rocket scientist; spam filtering algorithms are smart enough today to do better than a 20% false positive. Fix it!

I had similar experiences last year with AOL who put our long standing domain name in the junk mail the first time a customer got an email from us but it was easily fixed by the customer marking it as not junk. Not so lucky with Hotmail. Sometime in the last half of 2005 Hotmail changed things and stopped our emails getting through to long standing customers. Earlier in 2005 BTconnect did something which blocked our domain but a few calls from customers to BT fixed that permanently. I investigated my ISP which was Zen Internet and found they had changed their policy on reverse DNS and enabled it for us having initially refused. This did not help us with Hotmail though. The only way an email from our domain could get through was when we replied to an email from our customer so it was clear they were using a rather drastic filter which never got fixed. In the early part of 2006 I investigated some other failed deliveries and found one ISP in Australia unknowingly had included the Sorbs black list in their filter criteria. This is a particularly pernicious little list with one person in Queensland who maintains it if that is not too strong a word. He blocks whole IP ranges and asks people for donations to charity to unblock it, if he doesn’t like your email complaints he refuses to deal with you!
I went into this very extensively and found little difference between the attitude Sorbs demonstrates to its victims and the spammers! I think there is a place for blacklists that are used properly like Spamhaus but it is a technique that needs very careful application or the damage it does is worse than the disease. It is very easy to have your domain hijacked by the spamming industry especially if you register any domain controlled by Verisign. Recently I registered a dot com domain and the next day I was hit with a spam email offering free email lists for charities exactly the same type I got several years ago when I registered another dot com domain. (How do I know it came from Verisign? It used their name as the mailbox which is how I use the catchall domain to identify who uses my email address). The dot co dot uk domain registered at the same time has so far been free of unwanted emails. Needless to say we have never sent broadcast emails to anyone not even a long list in the C.C. part like some people do instead of using Blind Copy.

Ich finde Ihre Homepage sehr gut und fundiert. Die Informationen helfen mir bei einer Diplomarbeit für den Bereich der Medizinischen Dokumentation vielen Dank und weiter so.