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How's Your Consent; Single or Double?


With recent changes in privacy legislation, opt-in permission and  consent have

become an even more critical requirement in today's email industry. Let's have a quick look at the history of opt-in permission, and why it continues to be a win-win in the world of email.


Short History of Email Opt-In Permission:

LISTSERV inventor, L-Soft CEO and founder Eric Thomas, invented the confirmed opt-in method, more frequently known as "double opt-in", back in 1993, more than 25 years ago now. The introduction of double opt-in was so successful that it became the de facto industry standard for the subscription process.

This new method made it possible to confirm that the subscriber is who they claim to be, or at a minimum, that they control the email address submitted for the subscription. Once a subscription process has started, the LISTSERV software sends a confirmation email to the email address provided. This confirmation email provides specific instructions in order to confirm the subscription. If the subscription isn't confirmed, the potential subscriber is not enrolled and receives no further emails. This ensures accuracy in data (no bad email addresses), and that no-one can simply add another's email address to a mailing list without their knowledge or consent.

Eric's core idea for LISTSERV in 1986 was the automation of email list subscriptions and signoffs. This process had previously been handled manually and required an ever increasing level of manpower. With the launch of LISTSERV the world was introduced to the first fully automated email list management solution. It was initially built on the single 
opt-in method, still available today, enabling easy data migration and user management, but since the introduction of the preferred double opt-in method in 1993, the possibility of misuse became drastically reduced. Double opt-in promoted a strong level of confidence to the LISTSERV subscriber, assuring them that they would remain in control, and could determine whether to receive LISTSERV emails or not, and it also provided a simple way to unsubscribe from all future mailings..

The GDPR Relevance

It is beneficial to know about the double opt-in concept for many reasons. The new European regulation, GDPR, for instance, requires that the email recipient has given a specific and informed consent for you to send email. Here is a definition of consent as given in GDPR article 4:

"(11) 'consent' of the data subject means any freely given, specific, informed and unambiguous indication of the data subject's wishes by which he or she, by a statement or unambiguous indication of the data subject's wishes by which he or she, by a statement or by a clear affirmative action, signifies agreement to the processing of personal data relating to him or her;"

L-Soft Recommends

Naturally, L-Soft is a proponent of explicit prior permission and strongly recommends the use of double opt-in, even when legislation does not yet require it in some parts of the world. For the best results, always follow email marketing best practices and check the key 
legislation before engaging in email marketing activities. For example, if you reside in the US but have any recipients of your email marketing messages in the EU, you need to comply with the GDPR, even though the US CAN-SPAM Act does not require a prior consent. The same applies if you have recipients in Canada, as the Canadian anti-spam legislation, CASL, 
requires prior permission of the email recipients.


Pros and Cons

As with everything, even double opt-in has its pros and cons. The benefits are clear. The recipients who actively want to belong to your email list are the ones most likely to engage with your messages as well. This can mean higher response rates and satisfied list members. The primary disadvantage is that it requires the subscriber to confirm their subscription which can happen for many reasons, whether it be a spam filter sorting the confirmation mail to a junk folder, or if it simply goes unnoticed in the recipient's inbox.

That being said, it is generally not typical, but it can happen from time to time.

Design Your Process

Good design and clear communication can help avoid this pitfall. Well implemented signup forms and email message templates include all the essential elements of opt-in, confirmation and opt-out functions. Email list management or email marketing platforms, such as the ones that L-Soft and many others provide, make the signup, confirmation, 
permission tracking and other processes easy to work with and manage.

It Is a Win-Win Relationship

See your confirmation process as a step towards welcoming a new subscriber and to start a sender-subscriber relationship. And remember that welcome messages do generally maintain high open rates - so it is a great trust and branding opportunity as well - not just something required for compliance with legislation.

The work required to use permission confirmation is well worth it. Double opt-in is powerful because the sender and recipient have a confirmed connection - you "know each other," so to speak, and the subscriber now expects to receive messages from you. Double opt-in 
builds trust. Recipients are more likely to open messages from senders they know than those they never heard of or did not sign up for. Aim for the win-win with permission as the basis of the relationship.


Glossary of Permission Email Related Terms:  


  • AB-375/CCPA: California Consumer Privacy Act of 2018, CCPA, is a signed Assembly Bill, AB-375 Privacy: personal information: businesses, that will come in effect January 1, 2020. It grants a consumer rights to her or his own personal data.

  • Best Practice: Considered as commonly adopted best practice and code of email marketing among email communication practitioners and professionals. Permission-based email marketing is the current praxis to follow.

  • CAN-SPAM Act: The Controlling the Assault of Non-Solicited Pornography and Marketing Act, 15 USC Ch. 103 -  The CAN-SPAM Act, covers the requirements for the sending of commercial email in the United States. See also Definitions and Implementation Under the CAN-SPAM Act - 16 CFR Part 316. CAN-SPAM does not require prior opt-in.

  • CASL: Canada's anti-spam legislation, CASL S.C. 2010, c. 23. The CASL is Canada’s law on spam and other electronic threats. CASL requires prior opt-in.

  • Confirmed Opt-In (COI): Same as Double Opt-In. See Double Opt-In (DOI).

  • Confirmation Email: A message that is sent to the person who signed up for an email list in order to receive future email messages.

  • Confirmation Link: A link in the confirmation message (double opt-in) that the person who signed up for an email list needs to click to confirm the subscription and to receive future email messages.

  • Consent: Approval from a recipient to receive future email marketing messages from a particular sender. Consent provides the permission base to conduct email marketing.

  • Double Opt-In (DOI): The recommended procedure for subscribing email recipients to an email list or newsletter. Once a person requests to subscribe to a list, a confirmation email message is automatically sent to the supplied email address asking the person to verify that they have in fact requested to receive future mailings.

  • GDPR, The European General Data Protection Regulation: The GDPR, went in effect in May 2018 and covers protection and processing of personal data of natural persons in the European Union,

  • the EU.

  • Opt-In: An approach to email lists in which subscribers must explicitly request to receive email campaigns or newsletters, for example, via a signup form on a web page. Opt-in is the functions when someone is given the option to receive email.

  • Opt-Out: An approach to email lists in which recipients are included in email campaigns or newsletters until they specifically request not to be subscribed any longer. This method is not recommended and may in some cases be illegal. Opt-out is the function when someone unsubscribes from future messages and leaves the email list.

  • Permission: A recipient's prior consent for an email marketer or email list owner to send messages.

  • Single Opt-In (SOI): Recipient-initiated opt-in but unconfirmed subscription. Someone submit an email address to a signup form, but no steps are taken to make sure that this address belongs to

  • the person submitting it. Compare with Confirmed Opt-In (COI) or Double Opt-In (DOI).

  • Spam: Unsolicited commercial email. Unwanted, unsolicited junk email sent to a large number of recipients. It is not asked for or requested by the recipient.

  • Welcome Message: A message that is sent out to new subscribers of an email list, confirming that they are subscribed and, in some cases, giving additional information about the email list.


Please get in touch with us and propose updates or new terms. Simply drop us a line at:


Long Live Permission Email!

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