Knowledge about anti-spam

1.Glossary: Anti-spam. For details, see Wikipedia: Spam Anti-Spam technology.

2.Four Common anti-spam technologies

3.RBL Technology:

RBL is a Real-time Blacklist, or dynamic Blacklist. It is an anti-spam technique.

3.1 RBL principles and usage: Http://www.bitscn.com/netpro/firewall/200709/114002.html

To describe RBL's work process more vividly, draw a flowchart:

Assume that the RBL list uses the cbl Service of China Anti-Spam alliance. Its address is:Cbl.anti-spam.org.cn

3.2 introduction to common RBL lists: Http://840711.blog.51cto.com/69327/23533/

4. RBL and DNS

4.1 Association:When RBL is used to determine whether the IP address corresponding to the email server Domain Name of the mail sender is in the RBL blacklist address list, it is implemented through DNS query.

4.2 typical cases: When RBL encounters DNS hijacking: http://www.anti-spam.org.cn/AID/796

This article is from: China Anti-Spam Alliance (one of the most authoritative anti-spam service providers in China). It details the DNS hijacking (such as DNS hijacking of China Telecom) When RBL is used) the problem caused by "rejecting all incoming mail.