How Spam Works and Its Affects
1. How Spam is Sent.
Most, but not all, spam is sent via open relay. An open relay is an e-mail server that is "open" for third-party transfer of information. Open relay does have legitimate uses, such as providing remote access to a network, but unfortunately it is becoming more commonly used for sending spam. Here's how it works: The person sending the spam message connects to ISP (Internet Service Provider) A but inappropriately uses Company X's mail server to send the spam to a recipient using ISP B. Company X is in no way involved with the sender or the recipient, so this scenario is considered an open relay. Also, if a spammer uses open relay, it is more difficult, though not impossible, to track them. Note that BTInet does not use open relay.
2. How Spam Affects Company X.
In the above scenario, the sender of the spam e-mail message would cause unwarranted issues for Company X. By using Company X's resources, the spammer has "stolen" bandwidth and processing time from Company X that could have been directed to legitimate e-mail or other uses. In addition, the recipient of the e-mail may now have a negative perception of Company X because it looks like the spam e-mail originated from them. For these reasons, most companies understandably do not allow open relay through their system.
3. How Spam Affects the Recipient and their ISP.
Besides the likelihood that the recipient is not happy about receiving unwanted e-mail, spamming wastes the resources of both the recipient and their ISP (ISP B). These resources include processing and downloading time, storage space and bandwidth as well as staff time to deal with it.
4. How Companies are Fighting Spam.
Some organizations are committed to fighting spam by maintaining a record of confirmed mail servers that allow open relay. That record is commonly called a "blackhole list." These organizations allow an ISP to compare an e-mail message it received to the listing of known open relays. If the e-mail message came from one of these open relays, the ISP can refuse to accept the message. Check out how BTInet reduces spam for information on which of these "blackhole lists" BTInet is currently using.
5. Why Legitimate Companies Need to be Identified.
One side effect of using "blackhole lists" is that legitimate companies can mistakenly get caught in the loop. If a spammer inappropriately uses a company's mail server via an unsecured open relay and that mail server gets added to a "blackhole list," legitimate users of that company's mail server will be unable to send e-mail to an ISP that uses that "blackhole list."
