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November 2004 Newsletter of the
Front Range UNIX Users Group

Cndnsd Vrsn: 4 PM Thursday 11/11 ACS Room 123- Greylisting


Killing Spam with Greylisting

The next meeting of the Front Range UNIX Users Group (FRUUG) will be held at 4:00 P.M. on Thursday, November 11. Barb Dijker will talk about her success at Netrack using greylisting to reduce the amount of spam being accepted for her customers.

Greylisting takes advantage of the fact that most spam delivery engines don't queue mail if it is not immediately deliverable. When greylisting is integrated into a Mail Transfer Agent (MTA), it gives the initial connection with an unknown server an SMTP temporary failure notification. If that same server attempts to re-try the mail delivery at a later time, the mail is accepted and the server is added to a greylist.

The devil is in the details, and Barb's talk on greylisting will give an overview of the technique, how it is implemented, and details of integrating it with sendmail and other open-source MTAs. She'll also show how it works with other spam-prevention tools like Spam Assassin. Barb will relate how well it's been working for her at Netrack, discuss some caveats to consider when using it, as well as some open issues.

As long as Barb is talking about her favorite subject, spam, she'll give a brief overview of Sender Policy Framework, or SPF, what it is, and what it isn't.

About The Speaker

Barb Dijker has been fighting and analyzing spam for many years as a consultant, and involved fighting spam for Netrack, Inc., and was a long-time board member of the Colorado Internet Coop. She has given talks on spam around the globe and has served as an expert witness in a legal case involving spam.

Meeting Location

This meeting will be in room 123 of the CU Academic Computing Center building at Arapahoe and Marine Streets in Boulder. Marine St intersects Arapahoe at 38th St; the Computing Center is on the southwest corner.

See <> for map

Our Last Meeting

At our last meeting, Geoff Baysinger of Sun Microsystems talked about innovations in Sun's Java Desktop System, and demonstrated some of its central administration capabilities that allow administrators to manage large numbers of desktops from a central location.

Announcements, presentation slides, and writeups for past meetings are available in the FRUUG Meeting Archive.

Future Meetings

We're in the process of setting up a January meeting on home automation.

FRUUG Library Notes

We have several new books from Addison Wesley this month, and we're expecting to receive a chapter from their new book on sendmail milters to pass out at this month's meeting. In addition, O'Reilly is whisking us some anti-spam books to arrive in time for the meeting. The new books we have on hand at the moment are:

  • C++ Without Fear, from Addison Wesley
  • Imperfect C++, from Addison Wesley
  • Moving to the Linux Business Desktop, from Addison Wesley
  • UNIX Shells, By Example, from Addison Wesley

You may check out books using your business card as your library card; you must be on the membership list to check books out. Books are due at the meeting following the one in which they are checked out.

Remember that your FRUUG membership entitles you to discounts on your book orders from both New Riders Publishing and O'Reilly & Associates; refer to the FRUUG Web site for details.

Site Map Recruiter Info
February 15, 2009

February 2008: FRUUG Enters Quiescent Phase
After 27 years running, we're suspending operations.

Future Meetings:
None planned

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