How to setup E-mail Filtering?

You can block an e-mail using spam filters. There are many definitions of spam, but one particularly useful one is the following:

Spam is the electronic version of junk mail, and has been around since the Internet was created. E-mail filters are a way of filtering your e-mail to remove unwanted mail based on a variety of criteria. You can block any sort of e-mail, not just mail of a commercial nature. Blocked mail can be deleted automatically or sent to another e-mail address or script. These filters are quite flexible – some examples are provided after the instruction on how to add a spam filter below. All filters are cumulative.

Useful anti spam links:

http://www.spamrecycle.com/antispamthings.htm

http://spam.abuse.net/overview/whatisspam.shtml

http://www.cybernothing.org/faqs/net-abuse-faq.html#2.1

Also refer to Spam Assassin for another approach to dealing with spam.

To add an e-mail filter:

Click on the E-mail Filtering link in the Mail area.

Click on the Add Filter link.

Click on the required header field in the first drop-down list. These are the various fields in any e-mail message.

Click on the required filter action in the second drop-down list. This action will act on the text entered in the third field.

equals – match the text exactly (whole words only). “Credit” will block “Credit”.

matches regex – matches the text based on regular expression (regex) rules. Regular expressions are a powerful but complex area. You do not need to use regular expression filters for most circumstances. Refer to these two good introductory tutorials – Using Regular Expressions and Learning to Use Regular Expressions – for more information.

contains – match the specified text in any circumstance. “porn” will block “porn” and “pornography”.

begins with – match the specified text when it is the beginning of a word. “porn” will block “porn” and “pornography” but not “teenporn”.

Enter the filter text in the third field. This text is case sensitive.

Enter the destination for the filtered e-mail in the Destination field. There are three separate types of destination:

Destroy the e-mail – Enter Discard in the field.

Redirect to another address – Enter the e-mail address to which to redirect the e-mail.

Redirect to a script – Enter the full script path on the machine that hosts your web site.

Click on the Activate button.

Example:

To redirect all e-mail from “john@paradise.net”, enter: From, equals, john@paradise.net, david@corse.org.nz

To delete all e-mail from paradise.net, enter: From, contains, paradise.net, Discard

To delete all references to pornography, enter: Any Header, contains, porn, Discard

To discard all e-mail that Spam Assassin has marked as spam, enter: SpamAssassin Spam Header, begins with, yes, Discard