Understanding ISP Feedback Loops

Understanding ISP Feedback Loops
28 Dec 2020

Understanding ISP Feedback Loops

Internet Service Provider (ISP) refers to companies or corporations that provide people with access to the Internet at a standard rate. An ISP is responsible for establishing local, regional or even national connections to facilitate online transmission of data between users, ISPs and Internet servers. IAPsor Internet Access Providers are companies that provide Internet connectivity to their end users. They also provide different network services such as email access, domain name registration, webbing and services.

The ISP has a specific point of presence (PoP). PoP stands for Physical Access Point where service providers host their network servers, switches and routers. Companies providing Internet services have multiple access points to support their systems. ISPs are geo-targeted. The range of their services will depend on whether they are local, regional or national ISFs. Major service providers can communicate with each other through switching centers such as the Central City Exchange (MEAE) within the States.


The need for Internet service providers emerged after the Internet was initially used by government research centers and universities as an efficient way to exchange data and resources. The commercialization of the Internet required the creation of a company that could sell this service to the public. In 1990, the first ISP introduced the Internet in Brooklyn, Massachusetts. However, the events that led to this can be traced back to the early 1980s, when personal computers were commercialized and became popular devices in the office and then at home. By 1993, the University of Illinois had developed the first ever web browser known as Mosaic.


In order to connect to the Internet, everyone must provide a secure Internet connection from an Internet Service Provider. Once an ISP has established a wired or wireless connection at a specific location, they can create a private network in that area. Devices connected to this network, in turn, connect to the public network, which ultimately provides them with access to the Internet. When accessing the Internet, users indirectly go through the servers of the ISPs before being able to retrieve data from the main server of the website. When a browser sends a request to the device's DNS server to retrieve data from its local cache, when it detects that the requested data is not available, it forwards the request to the installed router, which forwards it to the ISP's servers. ISP servers, through the switching centers that work between large ISP companies, can send requests to the hosting ISP server, which receives data from the host site. The resulting data traces the steps of the initial request and is eventually returned to the browser. This allows users to easily browse various sites on the Internet.

Commercial use

Internet service providers provide Internet access for a fee. These companies usually charge on monthly and in some cases on yearly subscription basis. The monthly fee depends on a number of factors. Before subscribing to their services, it is important to pay attention to exactly what you need from your ISP. When choosing an Internet Service Provider, consider the number of users who will be using the connection, the ratio of claims and bandwidth. The geographic location of your home or office is also important because ISPs are geographically limited to certain areas and may not be able to provide their services in your area. More information about DSL, cable, and fiber optic cables is also important in deciding which type of ISP is best for a user's needs. Additional costs to the provider may be due to other circumstances that you may not need to provide the service.

A feedback loop (FBL) or sometimes called a complaint feedback loop, is an inter-organizational feedback form that a mailbox provider (MP) uses to forward complaints from its users to the sending organization. MPs can disseminate user complaints by posting spam buttons on their web pages, email clients or help desk services. The message sender is an organization, often an email service provider. Feedback loops are one way to report spam. The question of how FBL and how is the choice of the deputy. End users report abuse in their mailbox's message center to also facilitate filtering. Alternatively, users can submit abuse complaints directly by acting as mailbox providers.

Rationale Marketers looking to get their mail delivered have a double benefit: they can remove subscribers who do not want to receive such ads (clean up lists), and can analyze the number of complaints and, therefore, how well their ads meet expectations. market. Through unsubscribing users who are complaining, marketers decrease the overall rate of IP or domain complaints by ensuring that targeted mail is much more likely to reach the subscribers who actually want to receive it. ESPs, playing the role of sender, are very sensitive to how sending mail on behalf of their customers can affect their reputation. Monitoring the number of complaints is one way to control what users submit them.

One-click unsubscribe

The weak point of FBL is its relative asynchrony, which can cause crashes. There can be a long time interval between an ESP's FBL subscription and the recipient pressing the spam button. The interval between that click and the actual removal of the recipient's name from the list is much shorter, but can be noticeable in the case of large mailbox providers such as Gmail or AOL. Bulk messages may contain information on how to unsubscribe directly in the List-Unsubscribe: and List-Unsubscribe-Post: header fields. In addition to providing a more direct and better way to unsubscribe, it also allows you to distinguish unsubscribe from spam messages (for example, you can indicate that a message sent to a discussion list is spam while still being signed).


  • Reporting Spencer sends a message to Alice.
  • Alice complains to Isaac (her ISP or MP) about the message, for example by clicking the "Report Spam" button.
  • Isaac encapsulates the message either as part of the MIME format of the abuse report or (less commonly) as a separate part of the / rfc822 MIME message and sends it to Spencer if Spencer has signed up to receive this feedback.
  • As shown above, the process assumes that Spencer, in addition to being the author (or sender) of the message, is associated with the postmaster responsible for his mail domain. FBL subscriptions usually require postmaster authorization. An FBL Subscriber may or may not forward abuse reports to appropriate authors. If there are no subscribers for a given mail domain, Isaac may not submit a violation report at all. In fact, subscriptions must be completed one at a time, a tedious task that non-mass mailing domains might want to skip. RFC 6650 addresses the latter flaw by offering an automatic timely FBL subscription that can be triggered by submitting an unsolicited abuse report with additional directives (at least a way to unsubscribe).

    Ipsos noted that the majority of respondents to the spam reporting survey flagged messages as spam based solely on the subject and sender. For years, end users have been told not to trust email unsubscribe links, so many users click the spam button as an alternative to unsubscribing. Consequently, a spam message can act as an unsubscribe in some cases. One of the reasons you shouldn't follow unsubscribe links is to avoid confirming that the message was received and opened.

    Reporting formats

    The Abuse Report Format (ARF) is the standard format for FBL reports. An abuse report comprises of a human-readable portion followed by a machine-readable portion and the original message. The report is characterized by a Feedback-Type field, which values ​​may indicate abuse, fraud, virus, or other (other types are registered with the IANA). Microsoft using the name Junk Mail Reporting (JMR) also uses its own format. Google's Gmail is beta testing a non-traditional FBL with some ESPs. Gmail uses its own format - a summary report showing the amount of spam sent to a known sender. SendGrid reports that the Gmail FBL, developed and launched by Julian Tempelsman and Sri Somanchi, is effective at detecting spam that other anti-spam systems miss.


    Some say that the "Report Spam" button is often misused. The feedback loops do not meet the general anti-spam criterion that no more email messages are generated. Even if the amount of feedback is only a small fraction of the number of messages that ESP sends, most ESPs are not yet organized to handle this. Using the same button for both abuse reporting and unsubscribing involves guesswork from (automated) support. For example, it does not make it easy to tell the list owner that a particular message on the (unmoderated) list is in fact spam. Some FBLs do not provide the ability to automatically transmit feedback to multiple parties — the sender, ESP (if involved), or an upstream datacenter / network address provider — as the FTC currently interprets the "Follow the Money" strategy. Most ESPs offering a feedback loop do not include the tagged recipient email address in the report. This makes it impossible to remove the recipient from the mailing list they subscribe to. This ESP practice encourages mailing list providers to send customized messages to every recipient (as opposed to sending literally the same message to everyone), so that mailing list providers can extract the original recipient from the customized loopback message.