open source anti spam

Open Source Anti Spam

A computer that has been implanted with open proxy software is called a zombie and can form part of a botnet used by spammers.
Set your email program like microsoft outlook express to not display the preview panel (see outlook express menu item 'view' then 'layout') because just opening a spam email might be enough to send information back to the sender that your email address is valid.
Usually, open proxies are not detected until they have become so bogged-down with botnet traffic that they no longer have cpu time left to provide good performance for their owners' own tasks.
Spam Tip: Never open spam or attachments in a spam email.
An open socks proxy is a security hole used by spammers to hide their originating ip address.
Honeypots are used in the study of open proxies and other spam-related phenomena.
Postfix is an open-source mail transfer agent program and is an alternative to sendmail.
Open relay.
Open relays allow spammers to hide their identity.
openspf.
In spam terms it's a mailserver set up to appear to be an open relay, but it really isn't.
Spamassassin: An open-source spam filtering system currently maintained by the apache software foundation, and used by many small-to-medium-size isps, online businesses, and end-users.