1. Spam Filter Isp

An folder filled with spam messages. Email spam, also known as junk email, is a type of where unsolicited messages are sent. Many email spam messages are commercial in nature but may also contain that appear to be for familiar websites but in fact lead to web sites or sites that are hosting. Spam email may also include malware as scripts or other executable file. Spam is named after luncheon meat by way of a in which Spam in the sketch is ubiquitous, unavoidable and repetitive. Email spam has steadily grown since the early 1990s., networks of -infected computers, are used to send about 80% of spam. Since the expense of the spam is borne mostly by the recipient, it is effectively advertising.

Do not apply content-based spam filters to FBL or abuse@ accounts or you will discard the very messages. It goes over quota. 42go ISP-Manager 42go SPAM-Filter SQLiteWebAdmin. Index of HOWTOs/Tutorials. HOWTO Forums. Version 1.0 Author. Options QUOTA.

The legal status of spam varies from one jurisdiction to another. In the United States, spam was declared to be legal by the provided the message adheres to rules set by the Act and by the. Have attempted to recover the cost of spam through lawsuits against spammers, although they have been mostly unsuccessful in collecting damages despite winning in court. Spammers collect email addresses from chatrooms, websites, customer lists, newsgroups, and viruses that harvest users' address books.

These collected email addresses are sometimes also sold to other spammers. The proportion of spam email was around 90% of email messages sent, in the end of 2014. Contents.

Overview From the beginning of the Internet (the ), sending of junk email has been prohibited. Gary Thuerk in 1978 to 600 people. He was reprimanded and told not to do it again. The ban on spam is enforced by the / (ToS/AUP) of internet service providers (ISPs) and peer pressure.

It was estimated in 2009 that spam cost businesses around US$130 billion. As the scale of the spam problem has grown, ISPs and the public have turned to government for relief from spam, which has failed to materialize. In action Spam has several definitions varying by source. Unsolicited bulk email (UBE)—unsolicited email, sent in large quantities.

Unsolicited commercial email (UCE)—this more restrictive definition is used by regulators whose mandate is to regulate commerce, such as the U.S. Spamvertised sites Many spam emails contain URLs to a website or websites. According to a report in 2014, there are an average of 54 billion spam messages sent every day. 'Pharmaceutical products (Viagra and the like) jumped up 45% from last quarter’s analysis, leading this quarter’s spam pack. Emails purporting to offer jobs with fast, easy cash come in at number two, accounting for approximately 15% of all spam email. And, rounding off at number three are spam emails about diet products (such as Garcinia gummi-gutta or Garcinia Cambogia), accounting for approximately 1%.'

Most common products advertised According to information compiled by Commtouch Software Ltd., email spam for the first quarter of 2010 can be broken down as follows. Email Spam by Topic Pharmacy 81% Replica 5.40% Enhancers 2.30% Phishing 2.30% Degrees 1.30% Casino 1% Weight Loss 0.40% Other 6.30% 419 scams. Main article:, or image-based spam, is an obfuscation method by which text of the message is stored as a or image and displayed in the email.

This prevents text-based spam filters from detecting and blocking spam messages. Image spam was reportedly used in the mid-2000s to advertise ' stocks. Often, image spam contains nonsensical, computer-generated text which simply annoys the reader. However, new technology in some programs tries to read the images by attempting to find text in these images. These programs are not very accurate, and sometimes filter out innocent images of products, such as a box that has words on it.

A newer technique, however, is to use an animated image that does not contain clear text in its initial frame, or to contort the shapes of letters in the image (as in ) to avoid detection by tools. Blank spam Blank spam is spam lacking a payload advertisement.

Often the message body is missing altogether, as well as the subject line. Still, it fits the definition of spam because of its nature as bulk and unsolicited email.

Blank spam may be originated in different ways, either intentional or unintentionally:. Blank spam can have been sent in a, a form of for gathering valid addresses from an email service provider. Since the goal in such an attack is to use the bounces to separate invalid addresses from the valid ones, spammers may dispense with most elements of the header and the entire message body, and still accomplish their goals. Blank spam may also occur when a spammer forgets or otherwise fails to add the payload when he or she sets up the spam run. Often blank spam headers appear truncated, suggesting that computer glitches, such as or other may have contributed to this problem—from poorly written spam software to malfunctioning relay servers, or any problems that may truncate header lines from the message body.

Some spam may appear to be blank when in fact it is not. An example of this is the VBS.Davinia.B email worm which propagates through messages that have no subject line and appears blank, when in fact it uses HTML code to download other files. Backscatter spam. Main article: Backscatter is a side-effect of email spam, and. It happens when email servers are mis-configured to send a to the when rejecting or quarantining email (rather than simply rejecting the attempt to send the message). If the sender address was forged, then the bounce may go to an innocent party.

Since these messages were not solicited by the recipients, are substantially similar to each other, and are delivered in bulk quantities, they qualify as unsolicited bulk email or spam. As such, systems that generate email backscatter can end up being listed on various and be in violation of '.

Legality. See also: Sending spam violates the (AUP) of almost all. Providers vary in their willingness or ability to enforce their AUPs.

Some actively enforce their terms and terminate spammers' accounts without warning. Some ISPs lack adequate personnel or technical skills for enforcement, while others may be reluctant to enforce restrictive terms against profitable customers. As the recipient directly bears the cost of delivery, storage, and processing, one could regard spam as the electronic equivalent of 'postage-due' junk mail. Due to the low cost of sending unsolicited email and the potential profit entailed, some believe that only strict legal enforcement can stop junk email. The Coalition Against Unsolicited Commercial Email (CAUCE) argues 'Today, much of the spam volume is sent by career criminals and malicious hackers who won't stop until they're all rounded up and put in jail.' European Union All the countries of the have passed laws that specifically target spam. Article 13 of the (2002/58/EC) provides that the member states shall take appropriate measures to ensure that unsolicited communications for the purposes of direct marketing are not allowed either without the consent of the subscribers concerned or in respect of subscribers who do not wish to receive these communications, the choice between these options to be determined by national legislation.

In the United Kingdom, for example, unsolicited emails cannot be sent to an individual subscriber unless prior permission has been obtained or unless there is a previous relationship between the parties. The regulations can be enforced against an offending company or individual anywhere in the. The 's Office has responsibility for the enforcement of unsolicited emails and considers complaints about breaches. A breach of an enforcement notice is a criminal offence subject to a fine of up to £500,000.

Canada The has passed anti-spam legislation called the to fight spam. Australia In Australia, the relevant legislation is the, which covers some types of email and phone spam and took effect on 11 April 2004. The Spam Act provides that 'Unsolicited commercial electronic messages must not be sent.' Whether an email is unsolicited depends on whether the sender has consent. Consent can be express or inferred.

Express consent is when someone directly instructs a sender to send them emails, e.g. By opting in. Consent can also be inferred from the business relationship between the sender and recipient or if the recipient conspicuously publishes their email address in a public place (such as on a website). Penalties are up to 10,000, or 2,000 penalty units for a person other than a body corporate. United States In the United States, most states enacted anti-spam laws during the late 1990s and early 2000s.

Many of these have since been by the less restrictive ('CAN-SPAM'). Spam is legally permissible according to CAN-SPAM, provided it meets certain criteria: a 'truthful' subject line, no forged information in the technical headers or sender address, and other minor requirements. If the spam fails to comply with any of these requirements it is illegal. Aggravated or accelerated penalties apply if the spammer harvested the email addresses using methods described earlier. A review of the effectiveness of CAN-SPAM in 2005 by the Federal Trade Commission (the agency charged with CAN-SPAM enforcement) stated that the amount of sexually explicit spam had significantly decreased since 2003 and the total volume had begun to level off.

Senator, a principal sponsor, noted that 'Enforcement is key regarding the CAN-SPAM legislation.' In 2004, less than one percent of spam complied with CAN-SPAM. In contrast to the FTC evaluation, many observers view CAN-SPAM as having failed in its purpose of reducing spam. Other laws Accessing privately owned computer resources without the owner's permission is illegal under statutes in most nations. Deliberate spreading of computer viruses is also illegal in the United States and elsewhere.

Thus, some common behaviors of spammers are criminal regardless of the legality of spamming per se. Even before the advent of laws specifically banning or regulating spamming, spammers were successfully prosecuted under computer fraud and abuse laws for wrongfully using others' computers.

The use of botnets can be perceived as theft. The spammer consumes a zombie owner's bandwidth and resources without any cost.

In addition, spam is perceived as theft of services. The receiving SMTP servers consume significant amounts of system resources dealing with this unwanted traffic.

As a result, service providers have to spend large amounts of money to make their systems capable of handling these amounts of email. Such costs are inevitably passed on to the service providers' customers. Other laws, not only those related to spam, have been used to prosecute alleged spammers. For example, was indicted on stock fraud charges in January 2008, and pleaded guilty in March 2008 to charges of mail fraud, fraud in connection with email, and failing to file a tax return. Deception and fraud Spammers may engage in deliberate to send out their messages.

Spammers often use false names, addresses, phone numbers, and other contact information to set up 'disposable' accounts at various Internet service providers. They also often use falsified or stolen numbers to pay for these accounts. This allows them to move quickly from one account to the next as the host ISPs discover and shut down each one. Senders may go to great lengths to conceal the origin of their messages. Large companies may hire another firm to send their messages so that complaints or blocking of email falls on a third party. Others engage in of email addresses (much easier than ). The email protocol has no authentication by default, so the spammer can pretend to originate a message apparently from any email address.

To prevent this, some ISPs and domains require the use of, allowing positive identification of the specific account from which an email originates. Senders cannot completely spoof email delivery chains (the 'Received' header), since the receiving mailserver records the actual connection from the last mailserver's IP address. To counter this, some spammers forge additional delivery headers to make it appear as if the email had previously traversed many legitimate servers. Spoofing can have serious consequences for legitimate email users. Not only can their email inboxes get clogged up with 'undeliverable' emails in addition to volumes of spam, they can mistakenly be identified as a spammer. Not only may they receive irate email from spam victims, but (if spam victims report the email address owner to the ISP, for example) a naive ISP may terminate their service for spamming. Theft of service Spammers frequently seek out and make use of vulnerable third-party systems such as and open.

SMTP forwards mail from one server to another—mail servers that ISPs run commonly require some form of to ensure that the user is a customer of that ISP. Open relays, however, do not properly check who is using the mail server and pass all mail to the destination address, making it harder to track down spammers. Increasingly, spammers use networks of malware-infected PCs to send their spam. Networks are also known as (such zombifying malware is known as a bot, short for ).

In June 2006, an estimated 80 percent of email spam was sent by zombie PCs, an increase of 30 percent from the prior year. An estimated 55 billion email spam were sent each day in June 2006, an increase of 25 billion per day from June 2005. For the first quarter of 2010, an estimated 305,000 newly activated zombie PCs were brought online each day for malicious activity. This number is slightly lower than the 312,000 of the fourth quarter of 2009.

Brazil produced the most zombies in the first quarter of 2010. Brazil was the source of 20 percent of all zombies, which is down from 14 percent from the fourth quarter of 2009. India had 10 percent, with Vietnam at 8 percent, and the Russian Federation at 7 percent. Side effects. This article possibly contains. Please by the claims made and adding.

Statements consisting only of original research should be removed. (October 2015) To combat the problems posed by botnets, open relays, and proxy servers, many email server administrators pre-emptively block dynamic IP ranges and impose stringent requirements on other servers wishing to deliver mail. Must be correctly set for the outgoing mail server and large swaths of IP addresses are blocked, sometimes pre-emptively, to prevent spam. These measures can pose problems for those wanting to run a small email server off an inexpensive domestic connection. Blacklisting of IP ranges due to spam emanating from them also causes problems for legitimate email servers in the same IP range. Statistics and estimates The total volume of email spam has been consistently growing, but in 2011 the trend seemed to reverse. The amount of spam that users see in their mailboxes is only a portion of total spam sent, since spammers' lists often contain a large percentage of invalid addresses and many spam filters simply delete or reject 'obvious spam'.

Spam Filter Isp

The first known spam email, advertising a DEC product presentation, was sent in 1978 by Gary Thuerk to 600 addresses, which was all the users of at the time, though software limitations meant only slightly more than half of the intended recipients actually received it. As of August 2010, the number of spam messages sent per day was estimated to be around 200 billion. More than 97% of all emails sent over the Internet are unwanted, according to a Microsoft security report. Estimates that 85% of incoming mail is 'abusive email', as of the second half of 2007. The sample size for the MAAWG's study was over 100 million mailboxes.

A 2010 survey of US and European email users showed that 46% of the respondents had opened spam messages, although only 11% had clicked on a link. Highest amount of spam received According to, Microsoft founder receives four million emails per year, most of them spam. This was originally incorrectly reported as 'per day'.

At the same time, owner of the domain name, was receiving over one million spam emails per day. Cost of spam A 2004 survey estimated that lost productivity costs Internet users in the United States $21.58 billion annually, while another reported the cost at $17 billion, up from $11 billion in 2003.

In 2004, the worldwide productivity cost of spam has been estimated to be $50 billion in 2005. An estimate of the percentage cost borne by the sender of marketing junk mail is 88 percent, whereas in 2001 one spam was estimated to cost $0.10 for the receiver and $0.00001 (0.01% of the cost) for the sender. Origin of spam. Email spam relayed by country in Q2/2007. Origin or source of spam refers to the geographical location of the computer from which the spam is sent; it is not the country where the spammer resides, nor the country that hosts the spamvertised site. Because of the international nature of spam, the spammer, the hijacked spam-sending computer, the spamvertised server, and the user target of the spam are all often located in different countries.

As much as 80% of spam received by Internet users in and can be traced to fewer than 200 spammers. Main article: The U.S. Department of Energy (CIAC) has provided specific countermeasures against email spamming.

Some popular methods for filtering and refusing spam include based on the content of the email, DNS-based blackhole lists , enforcing technical requirements of email , checksumming systems to detect bulk email, and by putting some sort of cost on the sender via a or a. Each method has strengths and weaknesses and each is controversial because of its weaknesses.

For example, one company's offer to 'remove some spamtrap and honeypot addresses' from email lists defeats the ability for those methods to identify spammers. Combines many of the techniques to scan messages exiting out of a service provider's network, identify spam, and taking action such as blocking the message or shutting off the source of the message. In one study, 95 percent of revenues (in the study) cleared through just three banks. How spammers operate.