Spam is a commonly used term for unwanted messages in general, and especially for "Unsolicited (Bulk / Commercial) Email", as well as "Excessive Multi Posting" on Usenet News.
By setting up SpamaAssassin and Procmail configuration files.
Vance Kochenderfer has made a program to help you set up both.
Run /nyx/projects/bin/spamfilter (top,c,m,sspf in the menus)
and answer the questions you are asked.
Probably not. But, you can choose not to encourage it, by heeding the following advice:
HTML or Java/Javascript, since spammers can use
these to get a confirmation that you have received their spew.
The
Terms of Service (TOS)
does not allow you to post to usenet with a
forged email address, but as long as it is possible for
a human to deduce your identity, it is acceptable to "munge" the
From: address, in order to prevent automated software robots
from "harvesting" your real address.
Nyx has defined a special hostname for this purpose:
blackhole.nyx.net which loops back to the senders own
machine, whatever its name is.
If, for some reason, you don't like that idea, it is acceptable to munge your
address into a name that isn't valid, provided that it does
not end in nyx.net !
(As this would add to the burden of the mail machine, having to bounce the
mail to the - possibly forged - sender address)
Munging the From: address is done in different ways in the
individual newsreaders:
If you choose to munge your
From: address, you probably also should add a hint in your
signature,
to help legitimate correspondents figure out your real address.
With webpages, it is possible to encode your email address in such a way that it makes it harder (though not impossible) for the robots to harvest your real email address, by "HTML-encoding" it, like username@nyx.net - which Any Browser [TM] is able to decode into username@nyx.net - or by adding extra characters, and omitting the @-sign, as in "username at nyx dot net".
You can also present your email address as a picture, that is readable to humans using a graphical browser, but if you want a "clickable" link, you can html-encode the mailto:-tag, or use the CGI-email form.