SIDF and the numbers

By Larry Seltzer  |  Posted 2007-04-23 Print this article Print

There are technical difficulties with these standards, of course, especially with forwarding accounts. Many universities, for example, allow alumni to keep an e-mail address and forward the mail on to their own personal account. Many commercial services, like Spamex, work the same way. If I send mail "from" my (University of Southern North Dakota at Hoople) address but send it through my mail server, then its going to fail any reasonable authentication check. There really isnt a good solution to this.

But all that aside, in the years since the standards positions hardened, have they had any effect? Microsoft argues that they have. Last week at the AOTS conference in Boston they announced that SIDF blocks 20 million fraudulent messages. Now when Microsoft says "Sender ID" in cases like this they often mean "SPF" which is incorporated as part of SIDF. In fact, its probably complete overlap now.

Its possible, for example, for a spammer to put SPF records on their junk domain and use a proper envelope when sending it, and then to use FROM: and SENDER: headers in the message with "" in them. Sender ID would detect this, although the SPF test would pass. So if youre sending out spam and spoofing FROM: addresses to do it, make sure not to spoof a Sender ID domain.

Some people think the answer is to throw out the old Internet and build a new one. Click here to read more on the idea.

Microsoft throws out a lot of other numbers:
  • 98% of phishing messages are caught by Sender ID
  • 90% of e-mail marketers have implemented Sender ID
  • E-mail marketers who implement SIDF and have a positive reputation have "up to 85% fewer messages mistakenly marked as spam."
  • 3.8 billion out of the 4.5 billion messages sent to Hotmail every day are spam.
  • 300 million of those messages to Hotmail come from domains with SPF records.

The message is as much—maybe more—to e-mail marketers than anyone else, but the point is that SIDF and SPF have substantial implementation and are working to improve the e-mail system. I can believe this. I can also believe that Microsofts ability to promote SIDF through the massive Exchange Server community has, and will continue to have, a positive effect on adoption by business.

So about 2 and a half years out from the MARID collapse, SMTP authentication is progressing as a real-world tool but slowly. Very large mail providers and senders are using it and benefiting from it, Some day a tipping point will arrive where it will be realized, generally, that you need to implement authentication and deal with any technical problems that result, but were not there yet.

Editors Note: This story was updated to correct an error in the description of SPF. Security Center Editor Larry Seltzer has worked in and written about the computer industry since 1983. Check out eWEEK.coms for the latest security news, reviews and analysis. And for insights on security coverage around the Web, take a look at Security Center Editor Larry Seltzers Weblog. More from Larry Seltzer

Larry Seltzer has been writing software for and English about computers ever since—,much to his own amazement—,he graduated from the University of Pennsylvania in 1983.

He was one of the authors of NPL and NPL-R, fourth-generation languages for microcomputers by the now-defunct DeskTop Software Corporation. (Larry is sad to find absolutely no hits on any of these +products on Google.) His work at Desktop Software included programming the UCSD p-System, a virtual machine-based operating system with portable binaries that pre-dated Java by more than 10 years.

For several years, he wrote corporate software for Mathematica Policy Research (they're still in business!) and Chase Econometrics (not so lucky) before being forcibly thrown into the consulting market. He bummed around the Philadelphia consulting and contract-programming scenes for a year or two before taking a job at NSTL (National Software Testing Labs) developing product tests and managing contract testing for the computer industry, governments and publication.

In 1991 Larry moved to Massachusetts to become Technical Director of PC Week Labs (now eWeek Labs). He moved within Ziff Davis to New York in 1994 to run testing at Windows Sources. In 1995, he became Technical Director for Internet product testing at PC Magazine and stayed there till 1998.

Since then, he has been writing for numerous other publications, including Fortune Small Business, Windows 2000 Magazine (now Windows and .NET Magazine), ZDNet and Sam Whitmore's Media Survey.

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