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Spam Filtering
Various anti-spam techniques are used to prevent email spam (unsolicited bulk email). No technique is a complete solution to the spam problem, and each has trade-offs between incorrectly rejecting legitimate email ( false positives) as opposed to not rejecting all spam email ( false negatives) – and the associated costs in time, effort, and cost of wrongfully obstructing good mail. Anti-spam techniques can be broken into four broad categories: those that require actions by individuals, those that can be automated by email administrators, those that can be automated by email senders and those employed by researchers and law enforcement officials. End-user techniques There are a number of techniques that individuals can use to restrict the availability of their email addresses, with the goal of reducing their chance of receiving spam. Discretion Sharing an email address only among a limited group of correspondents is one way to limit the chance that the address will be "harve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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:Wikipedia:Spam Blacklist
Thesis Hi. Can anyone please tell me, whether thithesiscan be considered as a reliable source to expand Saadat Ali Khan I article. This is written by Ashirbadi Lal Srivastava, a historian. Also a forward to it has been written by Jadunath Sarkar, another historian. RRD (talk) 09:57, 5 May 2019 (UTC) :, can be used. It's a good text, though with numerous misprints. ''The Architecture of Lucknow and Oudh, 1722–1856: Its Evolution in an Aesthetic and Social Context'' by Banmali Tandan provides additional valuable info, from a different perspective. 10:24, 5 May 2019 (UTC) :: Cathis bookbe used as a reliable source? It has multiple authors, and I would cite the part written by Wolseley Haig. RRD (talk) 15:03, 6 May 2019 (UTC) :::I'm sceptical on that per WP:AGEMATTERS, and "British Raj" sources has been noted as problematic on this noticeboard. Gråbergs Gråa Sång (talk) 07:41, 7 May 2019 (UTC) :::Here is one example: Wikipedia:Reliable_sources/Noticeboard/Archive_172#A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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SpamCop
SpamCop is an email spam reporting service, allowing recipients of unsolicited bulk or commercial email to report IP addresses found by SpamCop's analysis to be senders of the spam to the abuse reporting addresses of those IP addresses. SpamCop uses these reports to compile a list of computers sending spam called the "SpamCop Blocking List" or "SpamCop Blacklist" (SCBL). History SpamCop was founded by Julian Haight in 1998 as an individual effort. As the reporting service became more popular, staff were added and the SCBL became more useful. It has commonly been the target of DDoS attacks and lawsuits from organizations listed in the SCBL. Email security company IronPort Systems announced its acquisition of SpamCop on November 24, 2003, but it remained independently run by Julian Haight. A small staff and volunteer help in its forum. IronPort agreed to become a division of Cisco Systems on January 4, 2007, effectively making SpamCop a Cisco service. Julian Haight left appro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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The Spamhaus Project
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. Anti-spam lists The Spamhaus Project is responsible for compiling several widely used anti-spam lists. Many internet service providers and email servers use the lists to reduce the amount of spam that reaches their users. In 2006, the Spamhaus services protected 650 million email users, including the European Parliament, US Army, the White House and Microsoft, from billions of spam emails a day. Spamhaus distributes the lists in the form of DNS-based Blacklists ( DNSBLs) and Whitelists ( DNSWLs). The lists are offered as a free public service to low-volume mail server operators on the Internet. Commercial spam filtering ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Open Mail Relay
An open mail relay is a Simple Mail Transfer Protocol (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. History and technology Until the 1990s, mail servers were commonly intentionally configured as open relays; in fact, this was frequently the installation default setting. The traditional store and forward method of relaying e-mail to its destination required that it was passed from computer to computer (through and beyond the Internet) via modems on telephone lines. For many early networks, such as UUCPNET, FidoNet and BITNET, lists of machines that were open relays were a core ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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DNSBL
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. A DNSBL is a software mechanism, rather than a specific list or policy. Dozens of DNSBLs exist. They use a wide array of criteria for listing and delisting addresses. These may include listing the addresses of zombie computers or other machines being used to send spam, Internet service providers (ISPs) who willingly host spammers, or those which have sent spam to a honeypot system. Since the creation of the first DNSBL in 1998, the operation and policies of these lists have frequently been controversial, both in Internet advocacy circles and occasionall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Hashbusters
A hash buster is a program which randomly adds characters to data in order to change the data's hash sum. This is typically used to add words to spam e-mails, to bypass hash filters. As the e-mail's hash sum is different from the sum of e-mails previously defined as spam, the e-mail is not considered spam and therefore delivered as if it were a normal message. Hash busters can also be used to randomly add content to any kind of file until the hash sum becomes a certain sum. In e-mail context, this could be used to bypass a filter which only accepts e-mails with a certain sum. Initially spams containing "white noise" from hash busters tended to simply exhibit 'paragraphs' of literally random words, but increasingly these are now appearing somewhat grammatical. See also * Cryptographic hash function * Bayesian poisoning * Locality-sensitive hashing In computer science, locality-sensitive hashing (LSH) is an algorithmic technique that hashes similar input items into the same ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Distributed Checksum Clearinghouse
Distributed Checksum Clearinghouse (also referred to as DCC) is a method of spam email detection. The basic logic in DCC is that most spam mails are sent to many recipients. The same message body appearing many times is therefore bulk email. DCC identifies bulk email by calculating a fuzzy checksum on it and sending that to a DCC server. The server responds with the number of times it has received that checksum. An individual email will create a score of 1 each time it is processed. Bulk mail can be identified because the response number is high. The content is not examined. DCC works over the UDP protocol and uses little bandwidth. DCC is resistant to hashbusters because "the main DCC checksums are fuzzy and ignore aspects of messages. The fuzzy checksums are changed as spam evolves" DCC is likely to identify mailing lists as bulk email unless they are white listed. Likewise, repeatedly sending the same email to a server increases its number in the server, and, therefore, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Checksum
A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify data integrity but are not relied upon to verify data authenticity. The procedure which generates this checksum is called a checksum function or checksum algorithm. Depending on its design goals, a good checksum algorithm usually outputs a significantly different value, even for small changes made to the input. This is especially true of cryptographic hash functions, which may be used to detect many data corruption errors and verify overall data integrity; if the computed checksum for the current data input matches the stored value of a previously computed checksum, there is a very high probability the data has not been accidentally altered or corrupted. Checksum functions are related to hash functions, fingerprints, randomization func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Phishing
Phishing is a type of social engineering where an attacker sends a fraudulent (e.g., spoofed, fake, or otherwise deceptive) message designed to trick a person into revealing sensitive information to the attacker or to deploy malicious software on the victim's infrastructure like ransomware. Phishing attacks have become increasingly sophisticated and often transparently mirror the site being targeted, allowing the attacker to observe everything while the victim is navigating the site, and transverse any additional security boundaries with the victim. As of 2020, phishing is by far the most common attack performed by cybercriminals, the FBI's Internet Crime Complaint Centre recording over twice as many incidents of phishing than any other type of computer crime. The first recorded use of the term "phishing" was in the cracking toolkit AOHell created by Koceilah Rekouche in 1995; however, it is possible that the term was used before this in a print edition of the hacker maga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Email Spoofing
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. Masked email is a different topic, providing a "masked" email address that is not the user's normal address, which is not disclosed (for example, so that it cannot be harvested), but forwards mail sent to it to the user's real address. The original transmission protocols used for email do not have built-in authentication methods: this deficiency allows spam and phishing emails to use spoofing in order to mislead the recipient. More recent countermeasures have made such spoofing from internet sources more difficult but not eliminated it; few internal networks have defenses against a spoof email from a colleague's compromised computer on that network. Individuals and businesses deceived by spo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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DMARC
Domain-based Message Authentication, Reporting and Conformance (DMARC) is an email authentication protocol. It is designed to give email domain owners the ability to protect their domain from unauthorized use, commonly known as email spoofing. The purpose and primary outcome of implementing DMARC is to protect a domain from being used in business email compromise attacks, phishing email, email scams and other cyber threat activities. Once the DMARC DNS entry is published, any receiving email server can authenticate the incoming email based on the instructions published by the domain owner within the DNS entry. If the email passes the authentication, it will be delivered and can be trusted. If the email fails the check, depending on the instructions held within the DMARC record the email could be delivered, quarantined or rejected. For example, one email forwarding service delivers the mail, but as "From: no-reply@". DMARC extends two existing email authentication mechanisms, Se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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DKIM
DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect forged sender addresses in email ( email spoofing), a technique often used in phishing and email spam. DKIM allows the receiver to check that an email claimed to have come from a specific domain was indeed authorized by the owner of that domain. It achieves this by affixing a digital signature, linked to a domain name, to each outgoing email message. The recipient system can verify this by looking up the sender's public key published in the DNS. A valid signature also guarantees that some parts of the email (possibly including attachments) have not been modified since the signature was affixed. Usually, DKIM signatures are not visible to end-users, and are affixed or verified by the infrastructure rather than the message's authors and recipients. DKIM is an Internet Standard. It is defined in RFC 6376, dated September 2011; with updates in RFC 8301 and RFC 8463. Overview The nee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |