Mail Abuse Information


1.7 E-mail Abuse

While the majority of this chapter focuses on the features and goodies that make e-mail so useful in the modern world, it is worth mentioning that e-mail is not without its problems. This section focuses on the abuses of e-mail in general, and Internet e-mail in particular. Although these issues – like all things Internet – are rapidly changing, anyone who is going to administer an Internet e-mail system should be aware of the possible problems and vulnerabilities of the technology.

1.7.1 Spamming

The most common abuse of the electronic mail systems of the world is the same as the most common abuse of the postal systems of the world: junk mail. Like most postal junk mail, the majority of junk e-mail is commercial advertising or some other unsolicited – and unwanted – garbage. On the Internet, sending out junk mail like this is popularly known as "spamming," with the junk mail itself called "spam" or unsolicited commercial e-mail (UCE).

What it Is

When people in the Internet community talk about spamming, they’re usually talking about a particular type of junk e-mail, and not just any piece of unwanted e-mail. The messages that get labeled as spam are typically commercial advertising for highly questionable (and often illegal) products and services: get-rich-quick schemes, miracle diets, and the like. The following example is only slight exaggeration of a typical spam message:


From: FreeCash, Inc.
Subject: FREE MONEY!!!!
Dear Friend -

Would you like to have free money? Yes?! Then call us now!

FreeCash, Inc. has just patented an AMAZING new form of LEGALLY generating FREE MONEY! You can take advantage of this INCREDIBLE new service by simply calling our TOLL FREE(*) phone number, which will get you in touch with our WORLD FAMOUS FINANCIAL EXPERTS! They will MAKE YOU RICH!

(*) only $19.95 per quarter minute! Wow!

Figure 1-10 A prime example of unsolicited commercial e-mail; a.k.a. "spam"

Of the millions of computer users who get garbage like this in their daily e-mail, practically nobody is asking for it. They get these messages for the same reason that they get junk mail from the postal service: somehow their name and address got put on a mailing list, and the firms that buy the mailing list think that they can make money off these people by offering various services to them.

Note a couple of things about the above message. First, notice that the To: address does not include the address of a particular user; the destination address (To: is either the address of the mailing list that includes the recipient’s address, or a totally meaningless placeholder. In most cases, the sender hides the true destination addresses of these messages by using the blind carbon copy (BCC:) feature available in most e-mail clients.

Second, notice that the return address (From: FreeCash, Inc.) does not conform to the address protocols that we looked at in Section 1.4 – you can’t reply to this message, because there is no valid return address. Seldom does junk e-mail have a legitimate return address, because the senders know that most recipients will simply reply to their advertisements with notes like "Take me off your list right now!" Spammers don’t want to download thousands of such messages whenever they distribute their ads, so they deliberately send their messages with only bogus addresses.

The nicer folks who send junk e-mail will at least include instructions that you can use to request to be removed from their mailing lists, but not all do. For that reason, it can be virtually impossible for you to stop the flow of junk to your e-mail mailbox once it begins.

It’s worth mentioning that receiving garbage advertisements in your daily e-mail is only half of the story with spamming. A second manifestation of this same problem involves Usenet newsgroups, the Internet’s community billboards. With newsgroups, spammers can send a single message to a multiple newsgroups and have it seen by all of the folks who regularly read messages posted there. Although this type of spamming is indeed annoying and decreases the usefulness of newsgroups, it is not as problematic to the Internet as e-mail spamming.

Why it’s Bad

E-mail spamming is worse than a simple annoyance that requires you to delete unwanted messages from your e-mail client. To understand why, again consider its paper alternative, junk mail.

While we think of postal junk mail as bad, it really isn’t. Senders of junk mail buy stamps to pay the postal service for each piece of junk that they send; the more junk mail is sent, the more money the postal service is receiving, and the less they have to charge the rest of us to send our letters and packages. Just as television commercials fund the networks and allow us to watch sitcoms for free, junk mail funds the postal service and allows us to pay a mere 19 cents to have a postcard carried thousands of miles across the continent and personally delivered.

However, the opposite is true for junk e-mail: in this case, it’s the recipient of the message – as well as the folks whose systems carry it across the Internet – who foot the bill. If you’re paying your Internet Service Provider (ISP) for your time online or the amount of server resources that you are using, then more junk e-mail means more time online to download it, more storage space on the server to store the messages, and more money out of your pocket – all for e-mail that you don’t want! Meanwhile, your ISP’s modems are being tied up by users like you who are downloading all of these unwanted messages, meaning that the ISP may have to add modems and phone lines or field complaints from customers who can’t get on line.

The damage of junk e-mail increases with its volume. In one widely-publicized case, a particular ISP was receiving 1.8 million messages per day from a single spammer; not surprisingly, that volume negatively affected the quality of the ISP’s service. As more and more of the Internet’s bandwidth is taken up by millions and millions of junk e-mails, connection speeds for everyone will suffer, and the usefulness of e-mail itself will decrease because of the shrinking percentage of legitimate messages.



Note: Another problem associated with spamming is the practice of using a stranger’s mail server to distribute junk e-mail. This problem, known as relaying, is covered in Section 1.7.2.

It should be noted again that not all advertising via e-mail should be considered "spam." Like all other mediums, the Internet and e-mail can be useful methods to distribute information about legitimate commerce. However, the dramatic increase in recent years of e-mail ads that are just plain garbage – as well as the widespread Internet backlash to that garbage – have caused a great deal of debate about what commerce does and doesn’t belong online. Like the rest of the Internet, the spam debate continues to evolve.