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> Spam Protection Guide - 02
Spam Protection Guide - 02
EMAIL - How Email Works
Email is not really that complicated, there are only a
few things to know about it. The first thing to know is that email being sent
to you lands first on your service provider (ISP) or hosting company's mail server
out in cyberspace. You choose to download it to your computer, usually when you
"check email". It doesn't come to your computer until you choose.
Email travels most commonly by using the Simple Mail Transfer
Protocol. This is indeed a very simple protocol, developed back in the 1980s,
and contains no provision for authentication since the goal was interoperability
between everyone. This is the SMTP line that you are asked to fill in when you
set up your email information in an email program, and you're essentially telling
the program where to go for the smtp "sending engine" to push your outgoing
email to its address across the Internet.
The address your email is going to is the POP, which is
the other field that you usually fill in in your email program, and POP stands
for Point Of Presence - it's a unique domain name (IP address), such as example.com,
and your little piece of it is the user@ part of the address.
So when you send email, your program goes to your smtp
provider (perhaps "mail.provider.com") and the small piece of smtp code
waiting there packages your email for travel through the Net, and sends it to
your recipient's POP (perhaps "user@example.com").
You don't need to know this to secure your email from exploitation,
but in three paragraphs you've learned how email works, and it's that simple.
You always need to have this information to set up your email account in your
email program, now you know why.
And now that you know about SMTP, you can appreciate one
of the things that made the Sobig.F virus such a massive attack in August - it
didn't even need to use your email program to send itself out, it came with its
own, very efficient SMTP code written into it, so all it needed was your open
Internet connection and it was free to use your computer to send out all the emails
it wanted, harvested from your computer. It made a million copies of itself within
the first few hours of its operation. By the way, we were not affected by the
virus, and you don't need to be either.
Email spammers - the people who send you all the junk email
- have in recent years become more closely allied with hacker techniques and perpetrators.
Spammers have hijacked other people's mail servers simply by finding open ports,
or by using your email form on your website if it was unprotected (and most were),
and they've done this quite deliberately as a way both to eliminate bandwidth
costs, and also to provide a cutout in the backtracking trail.
There's increasing evidence of spammers writing viruses
purely to send spam. And hackers are using spam techniques to propagate and camouflage
their viruses. Some experts believe Sobig.E is a spammers' virus designed to harvest
legitimate email addresses from users' computers.
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