An Internet Protocol address is a numerical label such as 192.0.2.1 that is assigned to a device connected to a computer network that uses the Internet Protocol for communication. IP addresses serve two main functions: network interface identification, and location addressing.
A subnetwork, or subnet, is a logical subdivision of an IP network. The practice of dividing a network into two or more networks is called subnetting.
A Domain Name System blocklist, Domain Name System-based blackhole list, Domain Name System blacklist (DNSBL) or real-time blackhole list (RBL) is a service for operation of mail servers to perform a check via a Domain Name System (DNS) query whether a sending host's IP address is blacklisted for email spam. Most mail server software can be configured to check such lists, typically rejecting or flagging messages from such sites.
Code Red was a computer worm observed on the Internet on July 15, 2001. It attacked computers running Microsoft's IIS web server. It was the first large-scale, mixed-threat attack to successfully target enterprise networks.
Various anti-spam techniques are used to prevent email spam.
Email spam, also referred to as junk email, spam mail, or simply spam, is unsolicited messages sent in bulk by email (spamming). The name comes from a Monty Python sketch in which the name of the canned pork product Spam is ubiquitous, unavoidable, and repetitive. Email spam has steadily grown since the early 1990s, and by 2014 was estimated to account for around 90% of total email traffic.
In Internet networking, a private network is a computer network that uses a private address space of IP addresses. These addresses are commonly used for local area networks (LANs) in residential, office, and enterprise environments. Both the IPv4 and the IPv6 specifications define private IP address ranges.
An open proxy is a type of proxy server that is accessible by any Internet user.
The Spamhaus Project is an international organisation based in the Principality of Andorra, founded in 1998 by Steve Linford to track email spammers and spam-related activity. The name spamhaus, a pseudo-German expression, was coined by Linford to refer to an internet service provider, or other firm, which spams or knowingly provides service to spammers.
In computer networks, a reverse DNS lookup or reverse DNS resolution (rDNS) is the querying technique of the Domain Name System (DNS) to determine the domain name associated with an IP address – the reverse of the usual "forward" DNS lookup of an IP address from a domain name. The process of reverse resolving of an IP address uses PTR records. rDNS involves searching domain name registry and registrar tables. The reverse DNS database of the Internet is rooted in the .arpa top-level domain.
SORBS was a list of e-mail servers suspected of sending or relaying spam. It had been augmented with complementary lists that include various other classes of hosts, allowing for customized email rejection by its users.
Email spoofing is the creation of email messages with a forged sender address. The term applies to email purporting to be from an address which is not actually the sender's; mail sent in reply to that address may bounce or be delivered to an unrelated party whose identity has been faked. Disposable email address or "masked" email is a different topic, providing a masked email address that is not the user's normal address, which is not disclosed, but forwards mail sent to it to the user's real address.
Cisco NAC Appliance, formerly Cisco Clean Access (CCA), was a network admission control (NAC) system developed by Cisco Systems designed to produce a secure and clean computer network environment. Originally developed by Perfigo and marketed under the name of Perfigo SmartEnforcer, this network admission control device analyzes systems attempting to access the network and prevents vulnerable computers from joining the network. The system usually installs an application known as the Clean Access Agent on computers that will be connected to the network. This application, in conjunction with both a Clean Access server and a Clean Access Manager, has become common in many universities and corporate environments today. It is capable of managing wired or wireless networks in an in-band or out-of-band configuration mode, and Virtual Private networks (VPN) in an in-band only configuration mode.
In networking, a black hole refers to a place in the network where incoming or outgoing traffic is silently discarded, without informing the source that the data did not reach its intended recipient.
In computer networking, the Composite Blocking List (CBL) is a DNS-based Blackhole List of suspected E-mail spam sending computer infections.
The Mail Abuse Prevention System (MAPS) is an organization that provides anti-spam support by maintaining a DNSBL. They provide five black lists, categorising why an address or an IP block is listed:
Email spammers have developed a variety of ways to deliver email spam throughout the years, such as mass-creating accounts on services such as Hotmail or using another person's network to send email spam. Many techniques to block, filter, or otherwise remove email spam from inboxes have been developed by internet users, system administrators and internet service providers. Due to this, email spammers have developed their own techniques to send email spam, which are listed below.
Messaging Security is a program that provides protection for companies' messaging infrastructure. The programs includes IP reputation-based anti-spam, pattern-based anti-spam, administrator defined block/allow lists, mail antivirus, zero-hour malware detection and email intrusion prevention.
The Kelihos botnet, also known as Hlux, is a botnet mainly involved in spamming and the theft of bitcoins.
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. Cold emailing is a subset of email marketing and differs from transactional and warm emailing.
