prepared by
Paul Hoffman
Internet Mail Consortium
Internet Mail Consortium Report: UCE-DEF
IMCR-002, July 1, 1997
Unsolicited Commercial Email (UCE) has become a major concern for Internet users due to the increasing amount of UCE that typical Internet users receive. Many proposals for technical and legislative remedies are being suggested, but few proposals define UCE or list its negative effects. This paper sets forth standard definitions and gives an overview of UCE effects, without proposing or supporting particular mechanisms for controlling their occurrence.
Unsolicited Commercial Email, or UCE, is Internet mail ("email") with commercial content that is sent to a recipient who has not requested it. A mail recipient may have at one time asked a sender for commercial email, but then later asked that sender not to send any more commercial email or otherwise not have indicated a desire for such additional mail; hence any commercial email sent after that request was received is also UCE.
A common term for UCE is "spam", although that term encompasses a wider range of intrusive transmissions. For instance, the term "spam" originated in the realm of Usenet news, not email. There, individuals cannot request or refuse commercial email, although some newsgroups explicitly permit or encourage its inclusion as a part of the group charter. Further many people say that any unsolicited, bulk email (for example, with religious or political content) would also be counted as part of "spam". It well may be that discussion of control mechanisms will need to include non- commercial, as well as commercial, bulk mail.
Internet Email is processed by origination, relay and destination system (host) operators, primarily transmitting messages with the SMTP mail standard. An Origination Operator is an organization or individual that is responsible for the host which places a new piece of email into the Internet. A Relay Operator mediates email transmission between origination and destination systems. A Destination Operator is an organization or individual that maintains or controls a service for recipients of email and for allowing recipients to access their mail using a mail user agent. Destination Operators may also provide relay services and almost always provide origination service for the same users who are recipients.
These specialized terms are used here instead of the single, more common "Internet Service Provider" (ISP) because tens of millions of people get their mail service from organizations that are not ISPs. Almost everyone who gets email at their desk at work use their employers as a Destination Operator, but those companies are not ISPs. Also, many people get their Internet mail through free accounts in public libraries, schools, and so on, and the organizations running those mail servers should be differentiated from ISPs because they often are offering email access as a public service.
In many cases, ISPs which provide basic connectivity have no direct part in the problems associated with UCE. On the other hand, all Internet mail operators must deal with UCE problems every day. Hence, the terms introduced here include organizations providing Internet mail service to employees, as well as libraries and schools providing free service for their "customers" and also includes ISPs that include email within their set of products.
A recipient is a person who receives email. (Programs can also receive email, but they do so on behalf of a person.) Most recipients usually receive email from two kinds of senders: other people, and Mailing List Agents. Some email addresses refer to a "role" within the organization (such as "sales" or "postmaster") and might have multiple people processing email sent to it, or might have a software program respond automatically. In either case, UCE must still be handled by the recipient.
A Mailing List Agent (MLA) is a software program that acts like a recipient, but does special processing upon receiving email: it resends the email to a list of recipients. Hence an MLA is a special form of email relay. Many MLAs are controlled by people, but some are completely automatic and involve no human intervention or decision-making.
MLAs are sometimes called "mailing lists" or "mailing list managers", although these terms do not define well the roles of the controlling software or of the people involved in controlling the software. Other terms, such as "listserv", are sometimes used generically but actually refer to specific implementations of MLAs.
Note that an MLA is not a recipient because it is not the final destination for the message, even though its email address might have been used for the UCE. Mail sent to an MLA will most likely be re-sent to many people, and those people are the recipients of the original mail, even though that mail has processed and re-sent by the MLA.
Although the senders of UCE defend it as having little difference from traditional bulk mail, it in fact is quite different: UCE shifts almost all the costs of the message onto the recipients and their Destination Operators. The negative effects of UCE can be categorized into the effects on recipients, on the recipients' Destination Operators, and on the Internet backbone in general. Secondary effects also are felt by Origination Operators.
Further, many senders of bulk UCE use tactics which are often viewed as devious, and probably illegal, in order to reduce the cost to the sender or even to hide the true identity of the sender. Instead, costs are shifted from the actual sender to the receiver and their Destination operator. These tactics, which are becoming more common, are described separately because they are only tangentially related to UCE itself. That is, these tactics can be used by senders of any kind of bulk email, not just commercial email.
End users are the ones who are most affected by UCE. The costs, to recipients, generally fall into two categories: real costs and social costs.
UCE costs money to every recipient, as if it was sent "postage due". Probably the most important negative effect of UCE is the financial cost incurred transmitting it from the Destination Operator's host to the recipient user's host, such as through a modem. Many users have to pay their Internet access providers by the minute. Even users with fixed-cost Internet accounts often have to pay for the phone time to connect to their Internet access providers.
Multiply these costs by the hundreds of thousands or millions of users that many pieces of UCE go to, and you can see that the cost to recipients is quite high, even without taking into account the considerable costs to Destination Operators and the Internet backbone.
There are other costs paid by all UCE recipients that are similar to recipients of bulk postal mail. For instance, there is the time lost sorting UCE from wanted mail, the time lost opening unwanted UCE that is disguised as email that the user might want to read, and so on. As the quantity of UCE increases, the cost of doing this sorting can become quite significant.
Widespread UCE has had a significant human cost as well. Many users know that posting to mailing lists or on Usenet news will likely cause them to receive UCE, so they no longer participate in what used to be the most vibrant communications medium on the Internet. The constant fear of irreversibly getting one's name on a mailing list has caused many people to avoid using them altogether.
Similarly, the act of having to sort through cleverly-worded UCE in order to find actual personal email has caused many people not to use email to its fullest potential. These types of effects are causing many new users to avoid checking their mail as often as they would otherwise like, again causing less use of what could be a valuable medium. Use of "filters" by a recipient's email software can reduce some of this pain, but cannot eliminate it. The current state of filtering technology cannot distinguish between legitimate, personal email and UCE.
The costs of UCE go well beyond the recipient. Each Destination Operator pays for each email message received because a message takes up a certain amount of the Destination Operator's connectivity and computer bandwidth. Further, if the message is stored by the Destination Operator for a recipient, the operator must pay for the storage and the maintenance of that storage. Although the cost of a single UCE email to an individual recipient might well be quite small, the aggregate cost can be considerable.
Depending upon their specific business model, Destination Operators handle the costs of UCE differently. If the Destination Operator is an Internet Service Provider, the costs of UCE are borne by the ISP's users, through higher prices or lower service. If the Destination Operator is an employer, the costs of UCE are often taken out of the general networking budget, meaning that UCE causes lower company profits. If the Destination Operator is someone offering a free public mail service, UCE causes them to be able to offer less service to their clients.
Many Destination Operators report that they bear an additional and considerable expense, one of having to educate people about the nature of UCE and why they are receiving it. Because UCE tends to diminish people's desire to use the Internet, they are more likely to complain about it to their Destination Operators.
UCE sent over the Internet backbone causes delays for all Internet users. Further, because most UCE senders use mailing lists that have outdated addresses on them, many messages are rejected ("bounced"), causing the intended Destination Operator to send a return response, which wastes more bandwidth.
Many of the complaints about UCE, by Destination Operators, stem from the common practice employed by UCE senders of misappropriating services. The methods of misappropriation, while technically easy to do, cause hundreds of thousands of dollars of damage to Destination Operators per year by shifting the burden of sending the UCE on Destination Operators who are unrelated to the UCE sender.
The typical way that a deceptive UCE sender misappropriates service is to offload return mail and complaint handling onto an unsuspecting Origination or Relay Operator by specifying one or more incorrect return addresses in the message itself. They route the UCE through an unrelated Origination Operator's SMTP service. Both of these actions are quite easy to do and can make the source of the message almost untraceable, particularly if the UCE sender is using a short-lived Internet account that was obtained for the purpose of sending this UCE. The account is used once, to do the sending, and is never accessed again. Hence, the sender need not care at all whether its use for this purpose is ascertained.
Beyond the basic cost of deceptive use, the result of the unwanted mailing often causes many complaints to be directed at the Destination Operator that should instead have been directed at the UCE sender. These complaints can cause significant damage to the Destination Operator, such as by filling up mailboxes on the mail hosts and reducing service to legitimate users of the Destination Operator.