One way of dealing with spam is having Gnus split out all spam into a ‘spam’ mail group (see Splitting Mail).
First, pick one (1) valid mail address that you can be reached
at, and put it in your From header of all your news
articles. (I've chosen ‘larsi@trym.ifi.uio.no’, but for many
addresses on the form ‘larsi+usenet@ifi.uio.no’ will be a
better choice. Ask your sysadmin whether your sendmail
installation accepts keywords in the local part of the mail
address.)
(setq message-default-news-headers
"From: Lars Magne Ingebrigtsen <larsi@trym.ifi.uio.no>\n")
Then put the following split rule in
nnmail-split-fancy (see Fancy Mail
Splitting):
(...
(to "larsi@trym.ifi.uio.no"
(| ("subject" "re:.*" "misc")
("references" ".*@.*" "misc")
"spam"))
...)
This says that all mail to this address is suspect, but if it
has a Subject that starts with a
‘Re:’ or has a
References header, it's probably ok. All the rest
goes to the ‘spam’ group. (This idea probably comes
from Tim Pierce.)
In addition, many mail spammers talk directly to your
SMTP server and do not include your email
address explicitly in the To header. Why they do
this is unknown—perhaps it's to thwart this thwarting
scheme? In any case, this is trivial to deal with—you just
put anything not addressed to you in the
‘spam’ group
by ending your fancy split rule in this way:
(
...
(to "larsi" "misc")
"spam")
In my experience, this will sort virtually everything into the right group. You still have to check the ‘spam’ group from time to time to check for legitimate mail, though. If you feel like being a good net citizen, you can even send off complaints to the proper authorities on each unsolicited commercial email—at your leisure.
This works for me. It allows people an easy way to contact me
(they can just press r in the usual way), and I'm not
bothered at all with spam. It's a win-win situation. Forging
From headers to point to non-existent domains is
yucky, in my opinion.
Be careful with this approach. Spammers are wise to it.