Dealing with spam
(Last updated Dec 13, 2006)
"Spam" not just a tasty meat product. It is also the common name for
unwanted email messages, usually advertisements, that show up in your
inbox. Many people receive hundreds of spam messages for each
legitimate email. Eventually a solution will be found.
Until then, these simple steps will cut down on the unwanted email
messages that you receive.
Avoid getting spam
- Keep your email address private. Never allow your email
address to be posted on the Internet. Even if your
address is only posted in a GIF file, you will still
get spam.
- When dealing with online vendors, use a secondary
email address instead of your main one. Many vendors will
send you spam if you purchase from them, and others will
sell your email address to spammers.
- Never reply to a spam message. This would only confirm
to the spammer that they have reached a live person, and
you will receive even more spam. Don't bother reporting
spam to the sender, the ISP, or the authorities. It's
usually a waste of time. Also, never set your mail reader
to reply automatically to incoming mail. This would turn
your computer into a beacon for spam.
- Do not put your email in any publications, such as books or
research papers. You will get spam from equipment vendors,
antibody dealers, and the like.
- Make sure "read receipts" are turned off. Otherwise, the
spammer can tell when you read the spam message. This
proves that a live person is reading their spam, and
guarantees you will get more. In Outlook, click Options
on the Tools menu, click the Receipts tab, and then select
the Returning Read Receipts option to turn off receipts.
In Pine, type 'sc' to reach the configuration screen.
The best way to eliminate spam is to change your email address
and keep it a secret. If no one knows your email address, you
will not get any spam.
Blocking spam
The email server at our institute uses Spam Assassin along
with some extra plugins to identify spam. The software uses
optical character recognition and can even identify those
spam messages that consist of nonsensical text accompanied by
an advertisement in an attached image. However, by default the
software doesn't delete your spam; it only marks the spam messages
by adding the word "***SPAM***" to the subject line. You must
take one additional step if you want your spam to be deleted
automatically. This can be easily done using the following
step-by-step procedure.
-
Telnet to the email server (engram) by typing the following
command in a DOS box:
telnet brni-jhu.org
(Or better yet, use ssh).
Use your normal login name and email password.
- Create a file called .procmailrc
by typing
pico .procmailrc
- Paste the following text into the .procmailrc file:
:0:
* ^X-Spam-Status: Yes
spam
(the character between two colons is the number zero).
- Hit Ctrl-X to save the file.
- Now, any message that Spam Assassin marks as spam will automatically
be saved in a special folder called "spam". You should check this
file occasionally in case a message gets misclassified. This is a
lot easier to do if your email client is set to use IMAP instead
of POP3.
Changing your spam sensitivity setting
If some spam is still getting through, or if real messages are being
classified as spam, change your spam sensitivity setting as follows:
- Telnet to the email server (engram).
- type cd .spamassassin and press
Enter.
- Edit your user preferences file by typing
pico user_prefs
- Move the cursor to the line that says "required_hits" and change
the number to something else. A higher number will allow more messages
through, while a lower number will classify more messages as spam.
- Press Ctrl-X when finished. Your preferences have now been
changed.
Blocking specific types of spam
Some types of spam can't be identified by Spam Assassin. Often this
spam can be blocked using special procmail rules.
If you're still getting spam after taking
all the above steps, let us know and we will change your account
so that his rules also apply automatically to you. Or just copy this
.procmailrc script into your home directory.
(You may have to edit it first).
If that doesn't work
Some spammers constantly change their "From" address. For example,
a company called "Superarray" (superarray.bz) sends us a lot of spam,
using a variety of different senders. If you receive a lot of spam
from one particular domain, let me know and I'll add them to our
firewall. This is an extreme method, since no one at the institute
will ever be able to deal with that company again.
If you have trouble
If you can't do these steps successfully, feel free to ask us to
do it for you. But please try it yourself first.
For more information about configuring your .procmailrc file,
click
here.