UC Irvine’sNew Anti-Spam

Measures

UC Irvine’sNew Anti-Spam

Measures

Keith ChongNetwork & Support Programming

Network & Academic Computing ServicesUC Irvine

August 9, 2005

Keith ChongNetwork & Support Programming

Network & Academic Computing ServicesUC Irvine

August 9, 2005

New Anti-Spam Measures

New Anti-Spam Measures

• Realtime Block List (RBL) from Spamhaus.org:• Spamhaus Block List (SBL): List of spam

sources and spam services.• Exploits Block List (XBL): List of computers

with proxies, viruses, and trojans installed.

• “Greeting delay” blocks connections from non-conforming mailers that send data too early.

• Greylisting temporarily rejects new senders. Compliant servers will return. Spammers are not likely to return.

• Unknown users blocked earlier in transaction.

• Rate limiting: 60 messages per minute and 10 concurrent connections on a per server basis.

• Realtime Block List (RBL) from Spamhaus.org:• Spamhaus Block List (SBL): List of spam

sources and spam services.• Exploits Block List (XBL): List of computers

with proxies, viruses, and trojans installed.

• “Greeting delay” blocks connections from non-conforming mailers that send data too early.

• Greylisting temporarily rejects new senders. Compliant servers will return. Spammers are not likely to return.

• Unknown users blocked earlier in transaction.

• Rate limiting: 60 messages per minute and 10 concurrent connections on a per server basis.

UC Irvine’s E-mail System

UC Irvine’s E-mail System

Effectiveness of Anti-Spam Measures

Effectiveness of Anti-Spam Measures

418,771418,771

143,817143,817

208,353 Accepted

190,446 Spam

19,972 Viruses

131,674 Accepted

11,307 Spam836 Viruses

Connections BlockedConnections Blocked

Connections BlockedConnections Blocked

New Preventive Measure

Blocked Connections

Spamhaus RBL 186,240

Greeting Delay 11,898

Unknown Users 9,426

Too Many Open Connections

6,115

Rate Limit Exceeded 10,793

Statistics for 7/29/2005Statistics for 7/29/2005

Questions & AnswersQuestions & Answers