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Security is also covered
on this page:
Security |
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E-mail that
is received but not wanted. Many people get very little
spam and do not realise how fortunate they are. They
probably have an email account with Sympatico, Cogeco,
Rogers, Gmail, Yahoo, Hotmail or other large ISP. These
companies go to a lot of trouble to minimize spam for
their customers. See below for some of the techniques
used. However, not all spam gets stopped and some wanted
mail never makes it through.
If you still get spam, there are some things you can
do.
SPAM
Prevention techniques
- Minimize
the number of people who have your e-mail address.
If someone has your address in their address book and
they get infected by a virus, then your e-mail address
could be all over the Internet in minutes. The fewer
people who have your address the less the chance of
this happening. The catch is that we all like to get
e-mails so this is not a good solution.
- Don’t give
your e-mail address to someone who will put it
on a web site. Even if there is no virus
involved, there are people who “harvest”
e-mail addresses by searching web-sites for e-mail
addresses. [More here].
They then collect them and sell them as a mailing
list to spammers. Note that this site has been configured
to prevent our
own
e-mail address being harvested. Other web site
operators can do the same.
- If you must do either of the above,
then either implement Spam management techniques (below)
or use expendable addresses. For example, use a hotmail
or Yahoo address and change it every few months.
Then give these addresses to everyone except a very
few.
- If you get a SPAM message from
someone who is not a highly reputable organization, do
not reply at all. Do not even click on their
link that says “click here to unsubscribe”.
If you did not subscribe in the first place, this
action will only signal them that you are silly enough
to answer so you’ll get more SPAM. Conversely,
for organizations like Sears, Staples, Future Shop,
Globe and Mail, etc, if you don’t want their
e-mail, you should unsubscribe. These and other reputable
organizations can be trusted to stop e-mail if requested.
- Hoax emails are in
effect spam - they are unwanted emails.
So before sending them on, be sure it's not a hoax.
More.
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Once spammers have your email address,
you need to reduce spam's nuisance value.
SPAM Management
techniques
Option 1
Use the SPAM management tools in your e-mail program. These
vary considerably but the following can be used for Outlook
Express 6. Others will be similar.
Select Tools>Message Rules>Mail… to
set up a Mail “Message Rule”.
Here are instructions to set up a typical example:
- Select the Conditions…, select “Where
the Message Body Contains Specific Words”
- Select the actions…, select “Move
it to the Specified Folder”
- Rule Description, click contains
specific words and under “Type specific
words…” type (e.g.) Viagra and
click Add then OK. Now click specified and
click (if this is the first time you are doing this) New
Folder – then type Spam to name
the folder. If this is not the first time, select Spam.
Then click OK.
- Name of the rule, enter a name - e.g.
Rule 1.
Now click OK. You have now created a single rule – if
mail arrives with Viagra in the body of the message
it will be moved to the Spam folder. You can then
look at this folder occasionally to make sure one of your
friends did not send an off-colour joke. Then delete all
these Spam messages.
Option 2
Use another e-mail program that has better spam filtering.
- Outlook (available
with Microsoft
Office) – more powerful than the Outlook Express
version but otherwise similar. Will import address information
from Outlook Express.
- Thunderbird e-mail – free – this
works quite differently but manages spam well.
More on e-mail.
Option 3
Use a Spam filtering program (like SpamBayes) – these
are not listed here since they require technical support.
Contact us if you’d like to pursue this approach. One
problem likely to occur with an add-on Spam filtering program
is a clash between two programs doing the same thing. For
example, between Outlook and/or Norton and the add-on program.
Such combinations are not recommended.
Option 4.
Use a SPAM filtering service. Note that the risk is that you'll
either get Spam still or you'll misss clean mail or you'll
have to sort mail in a "Junk-mail-box". Some examples:
- Eagle – includes
Barracuda’s
spam filter as part of its Internet service. Works
well.
- Use an external service like OnlyMyEmail -
Your incoming mail goes via their service and is forwarded
to a new account. Externally, the world sees up to three
e-mail accounts. Similar to Barracuda except that you can
set it up yourself. Price is $4.00US per month.
- Use a positive ID system to whitelist
approved email addresses and black-list unwanted ones.
One such system is called boxtrapper and
is available on Cobourg Internet web sites. Not everyone
likes working with this kind of system but it works well!
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If you have allowed a web site somewhere to list your
e-mail address, then someone else will find it (and others)
and sell the list to someone else who will then send you
Spam. The automated process to do this is called harvesting.
This can be slowed down by using methods to disguise the
e-mail address using scripts and/or graphics to show the
address (such as done on this site) but sooner or later your
e-mail address will find its way to a spammer. You can minimize
the chances of this happening by the following:
- Don't allow your email address to go on the Internet
(e.g. web site) unless you know that the web site designer
has disguised the address (like on Cobourg Internet sites).
- Change your e-mail address every 6 months or so (a pain).
- When sending emails, if you don't know all the recipients
personally, can you trust them to not sell or give away
their own list of addresses? So in this case, send mailing
lists to bcc (instead of "to" or "cc")
to hide all addresses except the recipients own.
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Hoaxes
If you have e-mail, sooner or later you will get a message
that says something like:
"Believe it or not, there is a new Virus that cannot
be stopped by Norton. It is really bad, it wipes out your
hard drive."
It will often include a reference from Bill Gates, Microsoft
or some credible sounding person or company who has issued
a warning. It will then tell you what you have to do to "fix" the
problem. These fixes are sometimes benign and sometimes cause
damage of their own. The hoax message will nearly always
beseech you to pass the message on to everyone you know.
These kinds of messages are nearly all hoaxes. (I've seen
many and there have been no real ones yet!)
There are other hoaxes that purport to let you know about
a health problem that you just have to know from an important
sounding doctor. These sometimes contain some truth but other "facts" are
just plain wrong.
The hoaxes cause little harm except clogging up the e-mail
system. But it is embarrassing when you find out after you've
forwarded a hoax to everyone! To see more on hoaxes, either
now or next time you get an e-mail that's probably a hoax,
click here.
Hoaxes are also usually listed at Symantec (and other security
companies). Go to their Security
Response page. At the top is a search box. Enter some
identifying text from the suspected e-mail (e.g. FREE M & M's)
and click "Search". If it is a hoax, the response
will confirm that and give details.
Hoaxes can often be half-true or sent willingly by people
- e.g. "Stop the tax on e-mail with Bill 602P" which
was never proposed but discussed at length on the Internet
since 1999. For more on these kinds of sites, see Urban
Legend. They also cover stories that may be true but
seem unlikely.
Another form of Hoax that is more dangerous (financially)
is Phishing. See security
page.
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Spam filtering techniques
A full analysis of spam fighting tecniques cannot be given
here, becuase even if I knew all the tricks, it would be
best not to make them public so spammers would know what
was being used against them. But some are well known:
- Identify spamming email servers. When spam email is detected,
the IP address of the email server can be identified. If
this source continues to send spam, it will be blacklisted.
Then other legitimate servers do not accept mail from them.
Occasionally, servers get blacklisted when they should not
have. Because a server may be shared by several sites, it
is in everyone's interest to not allow spammers on their
server or several sites could get "turned-off" to stop the
one spammer.
- Look for combinations of words, subjects and unusual
characters that are often used in spam. These may not be
just the words you think - they may be (for example) too
many uses of "bargain".
- Multiple emails from the same person in a short time
- the exact number varies but this is why personal email
account scannot and should not be used for large volumes
of email (e.g. a club newsletter). A business account from
an ISP will generally have a much higher limit - or maybe
no limit.
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