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What is Spam, and how do I stop it?
Spam is unwanted or junk e-mail, usually of a commercial nature. Spam, or UCE (unsolicited commercial
e-mail), is an increasingly serious problem for Internet users. Spam clogs inboxes, slows down mail
servers, and is in general a nuisance.
How spammers get your e-mail address
It is impossible to determine exactly how spammers get your e-mail address. Here are some of the more
common ways:
- Giving out your e-mail address online - Spammers can get your e-mail address if you give it
out in an online survey or while signing up for something online.
- E-mail harvesting - Spammers use automated programs (sometimes called spambots, spiders, or
trawlers) to harvest e-mail addresses from webpages. Examples of commonly harvested webpages include web-based
directories, bulletin boards or discussion groups. For example, if your e-mail address is in an online
directory of members in a professional or trade organization, a directory of your high school graduating
class, or something similar, your e-mail address can be harvested. If your e-mail address appears on
such a webpage, have it removed.
- To get an idea of whether spambots can find your e-mail address online, try entering your e-mail
address in a search engine, such as Google. If the search engine
comes up with any results, then your e-mail address is definitely exposed on the web. If a search
engine's software can find your address online, so can spammers.
- For an excellent in-depth description of how spammers harvest e-mail addresses and what you can do
to prevent this, see the Center for Democracy & Technology's
Why Am I Getting All This Spam
web page.
- Mailing lists - Spammers can obtain e-mail addresses from mailing lists.
- Usenet (newsgroup) groups - Newsgroups are a prime source of e-mail addresses for spammers.
- IRC and chat rooms - Spammers can obtain e-mail addreses from people using certain kinds of chat rooms.
This is done frequently by spammers, as many users in chat rooms are Internet-newbies and may not
be experienced in dealing with spam.
- Guessing - The shorter or more guessable an e-mail address is, the more likely it is to receive spam.
For example, user names like dave or jdoe would make for very bad e-mail addresses.
- Other - There are many other ways spammers can get e-mail addresses, including but not limited
to white and yellow pages, scams, and buying/swapping lists with other spammers. For a more
comprehensive list of ways spammers can get your e-mail address, go to
http://www.private.org.il/harvest.html
BCPL efforts to stop spam
BCPL.NET installed a Barracuda 400 anti-spam and anti-virus firewall in January of 2005. The
Barracuda sits between the Internet and our mail server, pre-processing all incoming e-mail before
relaying it on to the mail server. Incoming mail identified by the Barracuda as virus e-mail is blocked
before it can reach the mail server. Incoming mail identified as spam is forwarded to mailboxes on the
mail server, but with a "SPAM" tag added to the Subject line. For example, the Subject line of a spam
message might look something like this:
Subject: [SPAM] Wholesale prices on Vicodin
If you see that "SPAM" tag, you'll know that the Barracuda firewall identified the message as spam.
You may want to examine "SPAM" tagged messages for a while, until you're satisfied that the Barracuda
isn't tagging messages that aren't really spam. That's up to you.
No current technology is 100% accurate in identifying virus and spam e-mail, so don't expect miracles.
Do not relax your guard! Continue to be on the lookout for suspicious e-mail in your Inbox. Continue to
use anti-virus software on your PC, and continue to keep it up to date. The Internet is full of nastiness
these days. Regardless of what BCPL.NET tries to do to defend you from them, never forget that you are
your own final line of defence against the bad guys.
You'll probably see some spam e-mail that the Barracuda firewall misses and doesn't tag as
spam. You may also find a few messages with the "SPAM" tag that are not really spam. This should improve
as we learn to use the Barracuda's various features, and as the Barracuda itself learns from the thousands
of e-mail messages it processes every day.
We will gradually turn on more advanced features as we become more familiar with the Barracuda, and
will use BCPL.NET News messages to explain what those features are and how they
affect your e-mail. Stay tuned for future developments.
If you're interested in learning more about the capabilities of the Barracuda 400 spam and virus
firewall, visit the Barracuda Networks web site at http://www.barracudanetworks.com
For more information on the Barracuda, see our
Spam and Virus Firewall FAQ.
- Keep your e-mail address out of the hands of spammers.
Put simply: If the spammers don't know your address they can't send you spam. The best way to
avoid getting spam is to not give out your e-mail address. Once a few spammers get hold of your
address, you'll get a steadily increasing amount of spam. Spammers trade and sell lists of
addresses, so it doesn't take long for your address to become known to a large number of spammers.
- If you buy merchandise from an online store, you'll probably be required to enter your e-mail
address as part of the ordering process. Reputable online merchants won't share your e-mail
address with other online merchants without your permission, but not all online merchants are
reputable. Look carefully for a checkbox or button that lets you specify that you don't want
the merchant to give your address to anyone else. If there is no such option, search the
merchant's web site for a published privacy policy. If you aren't satisfied that your e-mail
privacy will be respected, either don't buy from that company, or use a "throw-away" address
as described below.
- Don't put your e-mail address on a webpage - If you have your own webpage, don't put your
address on it either in plain text or as a mailto: link. Instead consider creating a small
graphic that displays your address (but don't make it a link). Disguise your address something
like this: "jdoe at bcpl dot net" instead of "jdoe@bcpl.net". Or, utilize one of the free
javascripts that will disguise your address (for an example see
http://www.joemaller.com/js-mailer.shtml ).
- If you participate in a Web-based forum of any kind that displays your e-mail address, contact
the person in charge of the forum and ask if your address can be hidden. If not, stay away from
that forum.
- Use a throwaway e-mail address
Set up a "throw-away" e-mail account with one of the free
Web-based e-mail services like Hotmail,
Netscape, or Yahoo, and use
that address in newsgroups and mailing lists. When the amount of spam you receive at that address
gets out of control, discontinue the account and get a new one.
- Complain to the abuse or postmaster addresses of the originating domain
Almost all ISPs now have abuse addresses specifically for this purpose. If you
identify the origin as erols.com, for example, address your complaint to "abuse@erols.com".
Unfortunately, this isn't as straightforward as it might seem. The address on the "From:"
line of spam is almost never where the spam really originated. Spammers almost always use a
fake address on the "From:" line. If you receive spam that shows "jdoe@erols.com" on the
"From:" line, and if you complain to "abuse@erols.com", there is an almost 100% probability
that you have complained to the wrong place. Figuring out the true origin of spam can be a
hassle, but it is essential in order to know where to complain.
To determine the true origin you have to examine the "Received:" lines in the full message
header. Most mail programs don't normally show you the full header. You have to turn on
full header display, usually in the configuration or in one of the menus. For specific
instructions on how to view full headers in many different e-mail programs please go to:
http://www.wurd.com/cl_email_faq_spamfight.php
Even with the full header in front of you, it can still be pretty tough for the layman to
determine the origin of the e-mail. This is because most mass mail software adds one or more
bogus "Received" lines and other information to throw you off track. Even if you are able to
figure out which "Received:" lines are legitimate, you then need to do some research
(typically a "whois" lookup in the ARIN database at www.arin.net) to figure out where to
send your complaint. This is time-consuming, so we don't recommend it unless you are very
serious about taking action against spammers.
- Set up your own spam filter
Although filtering at the server level isn't practical, filtering within your own mail
program may be a viable alternative because it is completely within your control. All current
versions of the most popular PC and Macintosh based mail programs (Outlook Express, Netscape,
Eudora, Apple Mail, Entourage, etc.) have filtering capability. Consult the written or online
Help documentation for your specific mail program.
One approach is to set up your filters to accept mail only from addresses you consider "friendly",
i.e. from e-mail addresses that are known to you (this is sometimes called a white list)
. This will certainly stop spam, but unfortunately it also has the potential to stop legitimate
e-mail as well. We don't consider it a good solution, but many people do it.
A less stringent but more labor-intensive approach is to create filters that will block e-mail
containing specific words. For example, if your primary concern is spam with pornographic
content, then set up a filter to block e-mail containing words you consider to be objectionable. A
"forbidden words list" intended to block normal non-pornographic spam (commercial ads, for example)
is less straightforward because the words in such e-mail are not any different from the words you
might find in legitimate e-mail.
There are many types of commercially available anti-spam software. Newer versions of anti-virus
software (such as Mcafee or Norton) may contain anti-spam as part of security software package.
You can obtain this software online or at most computer stores.
Please note that WebMail, used by many BCPL.NET customers and BCPL staff, does not have filtering
capability. In order to filter you will have to use an e-mail program installed on your own
computer.
- Change your e-mail address
There is only one sure way to eliminate spam (at least for a while). Change your BCPL.NET username
(the part of your address in front of the "@"). Then, protect the new address as described
above. If you want to do that, decide what you want your new username to be (plus a second
choice in case your first choice is already taken), then contact the BCPL.NET Accounts Desk at
410-887-4172 or
. Give it careful thought first, though. If you change your
username, you will have to change it in your BCPL.NET login window, and in your e-mail
program. You will also have to notify everyone from whom you want to receive e-mail of your new
address, and you'll have to resubscribe to any e-mail mailing lists you're on.
In the final analysis, your best line of defense is the Delete function in your mail
program. I know it's annoying to receive spam, but it takes only a moment to delete it. For most
users this remains the most effective way to deal with spam.
On December 16, 2003, a new anti-spam law called the "Controlling the Assault of Non-Solicited
Pornography and Marketing Act of 2003" was signed into effect. This law is also known as the "Can Spam
Act of 2003".
A copy of the CAN-SPAM Act can be found on the FCC website via the link below. To view this
document, you will need the Adobe Acrobat
Reader software.
NEVER REPLY TO SPAM
Spam e-mail often contains the message "To remove yourself from this list, reply with REMOVE in the
subject line" (or words to that effect). DO NOT reply to any spam, UCE, or electronic chain
letter. As explained above, the address on the "From:" line is probably phony. This means your
"Remove" request won't go anywhere. In the few cases where the "From:" address is a real one, there is
increasing evidence that replying simply verifies to the spammer that he/she has your correct
address. This will just result in more spam being sent to your address, not less.
Some spam e-mail may direct you to fill out a form at a specific web site to have yourself removed
from the spammer's mailing list. While some of these may be legitimate, most are merely mechanisms
used by spammers to collect addresses for their mailing lists.
Do not retaliate
Do not attempt to fight back by directing mailbombs or other retaliatory measures at a spammer's
apparent e-mail address. Remember, the address on the "From:" line is probably forged, so your
retaliation will most likely be misdirected. In addition to wasting your time, you may clog some
innocent person's mailbox with your mail, and/or you may clog up BCPL.NET's mail system with mail
delivery error reports. Your misguided retaliation may also result in BCPL.NET e-mail being banned
from other sites on the Internet.
Mailbombs and similar measures are considered "denial of service" attacks, and are a very serious
offense. Any BCPL.NET customer caught mailbombing another site, no matter what the motivation or
provocation, will have his/her account terminated immediately.
Why are e-mails addressed to someone else coming to me?
The reason you may not see your address in the To line is because it doesn't have to be
there. There are actually 3 addressable fields in e-mail, To, CC, and BCC.
To and CC work as you might expect - when you receive an e-mail it will clearly show
all recipients placed in the To and CC fields, including yourself.
The BCC field, which stands for Blind Carbon Copy, is never shown to recipients. Addresses
written in this field WILL be delivered to, but will not be displayed in the e-mail itself.
Originally, BCC was used as a way for people to send out newsletters without everyone in the
To field being able to see each other's addresses. Lately spammers and virus writers have been
using it to trick users into thinking the ISP has misdelivered their mail. The bottom line is, if you have
received a message, you WERE written in as a recipient.
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