Opt-in email
is a term used when someone is not initially added to an emailing list and is instead given the option to join the emailing list. Typically, this is some sort of
mailing list
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 re ...
, newsletter, or advertising. Opt-out emails do not ask for permission to send emails, these emails are typically criticized as
unsolicited bulk email
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, unavoida ...
s, better known as spam.
Forms
There are several common forms of opt-in email:
Unconfirmed opt-in/single opt-in
Someone first gives an email address to the list
software
Software is a set of computer programs and associated documentation and data. This is in contrast to hardware, from which the system is built and which actually performs the work.
At the lowest programming level, executable code consists ...
(for instance, on a
Web page), but no steps are taken to make sure that this address belongs to the person submitting it. This can cause email from the mailing list to be considered spam because simple typos of the email address can cause the email to be sent to someone else. Malicious subscriptions are also possible, as are subscriptions that are due to spammers forging email addresses that are sent to the email address used to subscribe to the mailing list.
Confirmed opt-in (COI)/double opt-in (DOI)
A new subscriber asks to be subscribed to the mailing list, but unlike unconfirmed or single opt-in, a confirmation email is sent to verify it was really them. Generally, unless the explicit step is taken to verify the end-subscriber's e-mail address, such as clicking a special web link or sending back a reply email, it is difficult to establish that the e-mail address in question indeed belongs to the person who submitted the request to receive the e-mail. Using a confirmed opt-in (COI) (also known as a Double opt-in) procedure helps to ensure that a third party is not able to subscribe someone else accidentally, or out of malice, since if no action is taken on the part of the e-mail recipient, they will simply no longer receive any messages from the list operator. Mail system administrators and non-spam mailing list operators refer to this as ''confirmed subscription'' or ''closed-loop opt-in''.
Some marketers call closed-loop opt-in "double opt-in". This term was coined by marketers in the late 90s to differentiate it from what they call "single opt-in", where a new subscriber to an email list gets a confirmation email telling them they will begin to receive emails if they take no action. Some marketers contend that "double opt-in" is like asking for permission twice and that it constitutes unnecessary interference with someone who has already said they want to hear from the marketer. However, it does drastically reduce the likelihood of someone being signed up to an email list by another person. Double opt-in method is used by
email marketers to ensure the quality of their list by adding an extra stop in the verification process.
The
US CAN-SPAM Act of 2003 does not require an opt-in approach, only an easy opt-out system. But opt-in is required by law in many European countries and elsewhere. It turns out that confirmed opt-in is the only way that you can prove that a person actually opted in, if challenged legally.
Opt-out
Instead of giving people the option to be put in the list, they are automatically put in and then have the option to request to be taken out. This approach is illegal in the
European Union
The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ...
and many other jurisdictions.
Address authentication
Email address authentication is a technique for validating that a person claiming to possess a particular email address actually does so. This is normally done by sending an email containing a token to the address, and requiring that the party being authenticated supply that token before the authentication proceeds. The email containing the token is usually worded so as to explain the situation to the recipient and discourage them from supplying the token (often via visiting a
URL
A Uniform Resource Locator (URL), colloquially termed as a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifie ...
) unless they in fact were attempting to authenticate.
For example, suppose that one party, Alice, operates a website on which visitors can make accounts to participate or gain access to content. Another party, Bob, comes to that website and creates an account. Bob supplies an email address at which he can be contacted, but Alice does not yet know that Bob is being truthful (consciously or not) about the address. Alice sends a token to Bob's email address for an authentication request, asking Bob to click on a particular URL if and only if the recipient of the mail was making an account on Alice's website. Bob receives the mail and clicks the URL, demonstrating to Alice that he controls the email address he claimed to have. If instead a hostile party, Chuck, were to visit Alice's website attempting to masquerade as Bob, he would be unable to complete the account registration process because the confirmation would be sent to Bob's email address, to which Chuck does not have access. Wikipedia uses this mechanism too.
Best practice
The step of email address verification (confirmation) is considered by many
anti-spam
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 ...
advocates to be the minimum degree necessary for any opt-in email
advertising
Advertising is the practice and techniques employed to bring attention to a product or service. Advertising aims to put a product or service in the spotlight in hopes of drawing it attention from consumers. It is typically used to promote a ...
or other ongoing email communication.
See also
*
Closed-loop authentication
*
Email marketing
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 s ...
References
{{reflist
Spamming
Email