1. Dealing With Spam The email kind, not the Food product.

2. What is Spam? Unwanted/unrequested commercial email Sometimes for questionable, possibly illegal goods or services On large scale is a significant waste of time and resources

3. What isn’t Spam? Are viruses spam? Are phishing scams spam? Not really, they are a different kind of problem, but often spam filtering techniques will catch these emails as well

4. How to Avoid Spam Most spammers these day get email addresses via web crawlers Avoid putting your email address on web pages Beware web based message boards and web based mail list archives New software should be smart enough to obscure email addresses, but check first

5. Avoiding Spam If you need to list your email address in public, make it hard for machines to read Spell out parts, such as “kevin AT fnal.gov” instead of using an ‘@’ Create a.jpg or.gif image of your email address

6. Spam Filtering At Fermilab On the central email servers at Fermilab, all email from outside the lab passes through our spam filtering servers These servers pass all email through a program called SpamAssassin This inserts hidden headers with a “spam score” that email programs or other servers can filter on

7. Spam Filtering at Fermilab No email is blocked on the email gateways for spam content The IMAP servers by default deliver email with a spam score of 5 or higher to a folder called “Tagged Spam”

8. Tagged Spam If you don’t see your ‘Tagged Spam’ folder, you may have to subscribe to it In Netscape, Mozilla, or Thunderbird, go to the File menu and select Subscribe You can also access it via the Webmail interface Don’t forget to delete old spam occasionally to save quota space

9. How Spam Assassin Works SpamAssassin uses two basic types of tests, regular expression tests and Real-time Black hole List tests

10. Regular Expression Tests Test for known spam words or phrases “Get Rich Quick” “$$$$$” “From: big____@hotmail.com” Other sorts of tests like faking email from Outlook instead of spam generating software Subtle things like too many html color changes

11. Realtime Blackhole Lists Test the “received” headers to identify machines the message passed through Checks for Spammer owned machines Poorly configured email servers Known hacked machines Spam Assassin does not block on these, but “hits” == more spam score

12. Other Ways to Fight Spam Netscape/Mozilla/Thunderbird have Adaptive spam filtering The email client looks at the words in email you mark spam/not spam and learns how to classify better Its important to correct mistakes, just click the “Junk/Not Junk” button on the toolbar

13. Teaching Mail Filters I find it easier to configure Thunderbird to move its Junk to a separate folder This way I only have to look for spam in my inbox, and non-spam in my Junk folder Less brain overhead than checking the little junk icon on every message

14. Other Mail Filters If you see regular spams with a certain sender, subject or recipient, most modern mail clients have easy to use filtering built in Mail filters are now available on the Fermi IMAP servers as well To edit your IMAP filters, log on to the webmail interface, click on “Options”, then “Mail Filters”

15. For More Information http://computing.fnal.gov/email/spam/http://computing.fnal.gov/email/spam http://www.cauce.org/ http://spam.abuse.net/