Graymail is solicited bulk email messages that don't fit the definition of email spam (e.g., the recipient "opted into" receiving them). Recipient interest in this type of mailing tends to diminish over time, increasing the likelihood that recipients will report graymail as spam. In some cases, graymail can account for up to 82 percent of the average user's email inbox. [1] Graymail was described in 2007 [2] and 2008 [3] by researchers at Microsoft Research looking to improve spam filtering as “messages that could reasonably be considered either spam or good (by different email users)” hence the name “graymail” was chosen to signify the subjective nature of the classification. A 2008 paper presented at the Fifth annual Conference on Email and Anti-Spam (CEAS) describes graymail as "messages (such as email newsletters) that some users value and others prefer to block". [4] In 2011 a report by The Radicati Group referred to graymail as "newsletters or notifications that a user may have signed up for at one time but no longer wants to receive". [5]
Graymail differs from spam and can be identified by one or more of the following traits:
In addition there is often a timeliness component to graymail whereby the utility of the message expires or becomes out of date after a period of time. Shopping deals are a good example: they’re only valid for a fixed number of hours or days but are frequently not read or opened by the recipient until after the offer has expired.
Electronic mail is a method of transmitting and receiving messages using electronic devices. It was conceived in the late–20th century as the digital version of, or counterpart to, mail. Email is a ubiquitous and very widely used communication medium; in current use, an email address is often treated as a basic and necessary part of many processes in business, commerce, government, education, entertainment, and other spheres of daily life in most countries.
A mailing list is a collection of names and addresses used by an individual or an organization to send material to multiple recipients. The term is often extended to include the people subscribed to such a list, so the group of subscribers is referred to as "the mailing list", or simply "the list".
A whitelist or allowlist is a list or register of entities that are being provided a particular privilege, service, mobility, access or recognition. Entities on the list will be accepted, approved and/or recognized. Whitelisting is the reverse of blacklisting, the practice of identifying entities that are denied, unrecognised, or ostracised.
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.
Naive Bayes classifiers are a popular statistical technique of e-mail filtering. They typically use bag-of-words features to identify email spam, an approach commonly used in text classification.
Hashcash is a proof-of-work system used to limit email spam and denial-of-service attacks. Hashcash was proposed in 1997 by Adam Back and described more formally in Back's 2002 paper "Hashcash - A Denial of Service Counter-Measure". In Hashcash the client has to concatenate a random number with a string several times and hash this new string. It then has to do so over and over until a hash beginning with a certain number of zeros is found.
Greylisting is a method of defending e-mail users against spam. A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize. If the mail is legitimate, the originating server will try again after a delay, and if sufficient time has elapsed, the email will be accepted.
A bounce message or just "bounce" is an automated message from an email system, informing the sender of a previous message that the message has not been delivered. The original message is said to have "bounced".
Email marketing is the act of sending a commercial message, typically to a group of people, using email. In its broadest sense, every email sent to a potential or current customer could be considered email marketing. It involves using email to send advertisements, request business, or solicit sales or donations. Email marketing strategies commonly seek to achieve one or more of three primary objectives: build loyalty, trust, or brand awareness. The term usually refers to sending email messages with the purpose of enhancing a merchant's relationship with current or previous customers, encouraging customer loyalty and repeat business, acquiring new customers or convincing current customers to purchase something immediately, and sharing third-party ads.
The term opt-out refers to several methods by which individuals can avoid receiving unsolicited product or service information. This option is usually associated with direct marketing campaigns such as e-mail marketing or direct mail. A list of those who have opted out is called a Robinson list.
A challenge–response system is a type of 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 purported 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 receive a challenge.
DomainKeys Identified Mail (DKIM) is an email authentication method designed to detect forged sender addresses in email, a technique often used in phishing and email spam.
An email service provider (ESP) is a company that offers email marketing or bulk email services.
An email alias is simply a forwarding email address. The term alias expansion is sometimes used to indicate a specific mode of email forwarding, thereby implying a more generic meaning of the term email alias as an address that is forwarded in a simplistic fashion.
MailChannels is a Canadian technology company that specializes in email security for businesses and internet service providers (ISPs). Founded in 2004 by Ken Simpson and headquartered in Vancouver, British Columbia, the company operates in email security and the infrastructure market. The business provides a products and services designed to safeguard email systems against spam, phishing, and other harmful content. They guarantee the dependable delivery of legitimate messages and offer a mail relay API for numerous websites.
Outlook.com, formerly Hotmail, is a free personal email service offered by Microsoft. This includes a webmail interface featuring mail, calendaring, contacts, and tasks services. Outlook can also be accessed via email clients using the IMAP or POP protocols.
Backscatter is incorrectly automated bounce messages sent by mail servers, typically as a side effect of incoming spam.
Since spam occurs primarily because it is so cheap to send, a proposed set of solutions require that senders pay some cost in order to send spam, making it prohibitively expensive for spammers.
SmartScreen is a cloud-based anti-phishing and anti-malware component included in several Microsoft products: