Spamming is the use of messaging systems to send an unsolicited message (spam), especially advertising, as well as sending messages repeatedly on the same site. While the most widely recognized form of spam is email spam, the term is applied to similar abuses in other media: instant messaging spam, Usenet newsgroup spam, Web search engine spam, spam in blogs, wiki spam, online classified ads spam, mobile phone messaging spam, Internet forum spam, junk fax transmissions, social spam, spam mobile apps, television advertising and file sharing spam. It is named after Spam, a luncheon meat, by way of a Monty Python sketch about a restaurant that has Spam in every dish and where patrons annoyingly chant "Spam!" over and over again.
An open mail relay is an SMTP server configured in such a way that it allows anyone on the Internet to send e-mail through it, not just mail destined to or originating from known users. This used to be the default configuration in many mail servers; indeed, it was the way the Internet was initially set up, but open mail relays have become unpopular because of their exploitation by spammers and worms. Many relays were closed, or were placed on blacklists by other servers.
The Spam Prevention Early Warning System (SPEWS) was an anonymous service which maintained a list of IP address ranges belonging to Internet service providers (ISPs) which host spammers and show little action to prevent their abuse of other networks' resources. It could be used by Internet sites as an additional source of information about the senders of unsolicited bulk email, better known as spam.
A Domain Name System-based Blackhole List (DNSBL) or Real-time Blackhole List (RBL) is an effort to stop email spamming. It is a "blacklist" of locations on the Internet reputed to send email spam. The locations consist of IP addresses which are most often used to publish the addresses of computers or networks linked to spamming; most mail server software can be configured to reject or flag messages which have been sent from a site listed on one or more such lists. The term "Blackhole List" is sometimes interchanged with the term "blacklist" and "blocklist".
Various anti-spam techniques are used to prevent email spam.
alt.sex is a Usenet newsgroup – a discussion group within the Usenet network – relating to human sexual activity. It was popular in the 1990s. An October 1993 survey by Brian Reid reported an estimated worldwide readership for the alt.sex newsgroup of 3.3 million, that being 8% of the total Usenet readership, with 67% of all Usenet "nodes" carrying the group. At that time, alt.sex had an estimated traffic of 2,300 messages per month.
The Controlling the Assault of Non-Solicited Pornography And Marketing (CAN-SPAM) Act of 2003, signed into law by President George W. Bush on December 16, 2003, established the United States' first national standards for the sending of commercial e-mail and requires the Federal Trade Commission (FTC) to enforce its provisions.
TMDA is an open-source software application designed to reduce the amount of junk email a user receives. TMDA's main difference from other anti-spam systems is the use of a controversial challenge/response system that bulk mailing machines and programs are either unwilling or unable to answer.
Email spam, also known as junk email, is unsolicited messages sent in bulk by email (spamming).
Sender Policy Framework (SPF) is an email authentication method designed to detect forged sender addresses in emails, a technique often used in phishing and email spam.
A joe job is a spamming technique that sends out unsolicited e-mails using spoofed sender data. Early joe jobs aimed at tarnishing the reputation of the apparent sender or inducing the recipients to take action against them, but they are now typically used by commercial spammers to conceal the true origin of their messages and to trick recipients into opening emails apparently coming from a trusted source.
A spambot is a computer program designed to assist in the sending of spam. Spambots usually create accounts and send spam messages with them. Web hosts and website operators have responded by banning spammers, leading to an ongoing struggle between them and spammers in which spammers find new ways to evade the bans and anti-spam programs, and hosts counteract these methods.
Disposable email addressing, also known as DEA or dark mail, refers to an approach where a unique email address is used for every contact or entity. The benefit is that if anyone compromises the address or utilises it in connection with email abuse, the address owner can easily cancel it without affecting any of their other contacts.
Email harvesting is the process of obtaining lists of email addresses using various methods. Typically these are then used for bulk email or spam.
SORBS is a list of e-mail servers suspected of sending or relaying spam. It has been augmented with complementary lists that include various other classes of hosts, allowing for customized email rejection by its users.
A challenge–response system is a type of spam filter that automatically sends a reply with a challenge to the (alleged) sender of an incoming e-mail. It was originally designed in 1997 by Stan Weatherby, and was called Email Verification. In this reply, the sender is asked to perform some action to assure delivery of the original message, which would otherwise not be delivered. The action to perform typically takes relatively little effort to do once, but great effort to perform in large numbers. This effectively filters out spammers. Challenge–response systems only need to send challenges to unknown senders. Senders that have previously performed the challenging action, or who have previously been sent e-mail(s) to, would be automatically whitelisted.
Backscatter is incorrectly automated bounce messages sent by mail servers, typically as a side effect of incoming spam.
People tend to be much less bothered by spam slipping through filters into their mail box, than having desired e-mail ("ham") blocked. Trying to balance false negatives vs false positives is critical for a successful anti-spam system. As servers are not able to block all spam there are some tools for individual users to help control over this balance.
A cold email is an unsolicited e-mail that is sent to a receiver without prior contact. It could also be defined as the email equivalent of cold calling.
