Internet and e-mail policy and practice
including Notes on Internet E-mail


Click the comments link on any story to see comments or add your own.

Subscribe to this blog

RSS feed


25 Oct 2009

How do you test spam filters? Email

(Thanks to Chris Lewis for permission to adapt this)

Everyone who uses e-mail needs spam filtering, and some filters definitely work better than others. Some people we know were trying to design tests of filter quality, which turns out to be extremely difficult.

What one might call 'filtering quality' assessment, should be the very very last step after "does it have the features I want?", "does it install/is it supported/supportable?", "does it crash?", "does it make lots of stupid mistakes?", "is it likely going to compare favorably with what we already have?".

You have to do the latter before the former. The latter is relatively easy. The former is what people keep asking about, and is the really really hard part to do right.

See more ...

  posted at: 00:24 :: permanent link to this entry :: 0 comments
Stable link is

07 Oct 2009

The Internet Archive Really Is Reliable

A recent message in the Risks Digest called Risks of believing what you see on the WayBack Machine ( claims that:

I have now encountered 2 legal cases in 3 months in which a plaintiff saw images on the WayBack Machine ( and believed that they indicated events in the past that never happened.

This is a big deal in legal circles, since is widely used in court cases to show the state of a web site at a given time, which can be critical in, for example, cases where the site shows prior art for a patent or infringing copies of copyrighted material. If the archive entries aren't reliable, all of these cases are thrown into doubt. Needless to say, it would be many defendants' dream come true if courts were to stop accepting archived copies.

I have analyzed the material cited in the article and find that the archive is fine, and his claims to the contrary are somewhere between disengenuous and deliberately misleading. Here's why.

See more ...

  posted at: 21:31 :: permanent link to this entry :: 0 comments
Stable link is


My other sites

Who is this guy?

Airline ticket info

Taughannock Networks

Other blogs

It turns out you don’t need a license to hunt for spam.
28 days ago

A keen grasp of the obvious
Italian Apple Cake
586 days ago

Related sites

Coalition Against Unsolicited Commercial E-mail

Network Abuse Clearinghouse

My Mastodon feed

© 2005-2020 John R. Levine.
CAN SPAM address harvesting notice: the operator of this website will not give, sell, or otherwise transfer addresses maintained by this website to any other party for the purposes of initiating, or enabling others to initiate, electronic mail messages.