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.
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
