What is Spam?
Spam, also referred to as junk, is unsolicited messages sent electronically, such as e-mails, SMS or forum messages. The recipient receives messages without having given consent. The content of the message is often of a commercial and promotional nature.
Spam may also include phishing messages, or messages containing malware such as viruses and trojans. The process of sending spam is called spamming and the person sending these messages is called a spammer.
Most spam is sent in the form of e-mails. E-mail spam is also known as Unsolicited Bulk E-Mail (UBE) or Unsolicited Commercial E-Mail (UCE).
The word spam originated from the brand name for canned meat called “Spiced Ham”. Spam only got its current meaning through the British comedy series “Monty Python’s Flying Circus”.
In addition to email spam, spamming search engines is also very prevalent. The purpose is to rank a website higher for a keyword and increase the flow of visitors, resulting in higher advertising/affiliate revenue or product sales.
Sending unsolicited emails is illegal in most countries and it is often difficult to find who is responsible. E-mail providers setup spam filters to auto detect spam and flag suspicious messages which are then moved to a different folder. The problem with these filters however is that they do not necessarily recognize every suspicious message, or mistakenly flag non-spam e-mails as spam.
There are numerous intelligent algorithms that automatically maintain the spam filter and reduce the maintenance effort for the user or provider. Spam filters developed and maintained by the e-mail provider have the advantage to sort out e-mails before they are delivered to the user. As a result, they do not take up a lot of bandwidth and do not end up clogging local mailboxes. The combination of local and network-side spam filters always results in a better solution.
The criteria for flagging unwanted messages includes:
- Known blacklisted IP addresses owned and operated by spammers
- Fake or masked sender addresses, also known as spoofing
- Suspicious text in the content or in the subject line of an email
Anti-spam lists are usually used as the basis for spam filters. The Spamhaus project is known for having the best anti-spam lists in the world.