The Importance of Double Opt-In: A person flies a paper airplane with a green checkmark to follow behind an identical paper airplane toward a computer screen with an open mail envelope.

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The Importance of Double Opt-in

By: Holly Kindzierski, Copywriter | Jan 12, 2024 | 3 Minute Read

In the realm of digital marketing, email marketing has proven to be a powerful tool, boasting an average conversion rate of 28.04% in 2022 compared to the overall average of 2.35%. To harness the true potential of email marketing, it is essential to adopt practices that foster genuine engagement. Enter double opt-in for marketing emails. 

Unlike single opt-in, double opt-in requires an additional confirmation step from subscribers, ensuring that they are genuinely interested and have explicitly granted permission to receive your communications. Through this approach you can enhance email deliverability rates, lower bounce rates, and cultivate trust and credibility with your audience, ultimately maximizing the effectiveness of your email marketing efforts.

Single Opt-in vs. Double Opt-in

Single Opt-in vs. Double Opt-in

Let’s start by chatting about what these terms actually mean. Single opt-in subscriptions allow users to subscribe to mailing lists without confirming that the email entered belongs to them. With confirmed, or double opt-in, the person entering that email address must then log in to their email and confirm that they do in fact want to sign up for the mailing list in question. 

While both practices have been around for a long time, double opt-in has risen to prominence in the last decade as best practices evolve to better serve businesses and customers alike. 

Why Enable Double Opt-in

Single opt-in systems invite chaos, allowing spam bots to exploit easy signups using fake email addresses, pranksters to weaponize signups, and legitimate users to inadvertently opt-in without realizing. While some argue that single opt-in increases engagement by capturing a wider audience, the risks outweigh the benefits. 

Implementing double opt-in ensures that potential customers confirm their interest, resulting in high-quality leads and a clean email list, reducing the likelihood of being marked as a spam sender. With 45.37% of emails labeled as spam, being labeled as such can ruin your marketing campaign and potential conversion rate of 28.04%. 

Additionally, double opt-in leads to more legitimate subscribers, requiring fewer email sends and less list cleaning, ultimately saving money and avoiding "dead" contacts in the email list.

So - Are There Any Downsides?

People move quickly on the internet. In a world where an 8 word email title is almost too long to catch someone’s attention and the top social platform is an app that was popularized through hosting 60 second videos, extra steps are risky.

By enabling double opt-in, you are adding an extra confirmation layer to get people on your list, and it is true - 20% of people do not click that confirmation link.

While that can be a scary thing to hear for any business, think about it this way: those people who confirm their email are more likely to open the marketing messages you send their way and click the links within. They are invested in what you produce. So by sacrificing a little bit of quantity, you get a lot more quality and that is a very good thing!

How to Enable Double Opt-in

Now that you’ve heard the pros and cons and (we hope) have decided to commit to double opt-in, how do you enable this feature? It is of course a little different for every platform, but we’ll guide you through the process with three of the major players in email marketing.




Good news: if you’re using Klaviyo, double opt-in is the default setting! You don’t have to do anything when sending out emails or sms - your customers will have to double opt-in by default.

If you want to change this, you’ll have to enable single opt-in.




To enable double opt-in on Mailchimp, do the following:

  1. Select your Audience
  2. Click Audience dashboard.
  3. If you have more than one audience, click the Current audience drop-down and choose the one you want to work with.
  4. Click the Manage Audience drop-down and choose Settings.
  5. Click Audience name and defaults.
  6. Under Form Settings, check or uncheck the box next to Enable double opt-in as needed.
  7. Click Save Audience and Campaign Defaults.




To enable double opt-in on Hubspot, do the following:

  1. In your HubSpot account, click the settings settings icon in the main navigation bar.
  2. In the left sidebar menu, navigate to Marketing > Email.
  3. Click the Double opt-in tab.
  4. Click to toggle the Send double opt-in email switch on to enable this feature. In your settings, you can customize the following details:
    1. Sender: use the dropdown menu to specify who the email is sent from.
    2. Double opt-in email language: use the dropdown menu to select the language for your email.
    3. Subject line: customize the subject line of your double opt-in confirmation email. You'll see a preview of how the email will render at the bottom of the pane.

Look Forward to Quality Leads

Look Forward to Quality Leads

Don’t get drawn into that promise of quantity through single-opt in, as enticing as it may seem. By setting up double opt-in for your lists, you can look forward to a clean email list full of quality leads who are going to support your business for a long time to come. And if you’re having trouble interacting with that audience, reach out to your friendly neighborhood Arctic Leaf representative!


Looking for other email marketing best practices for high deliverability rates? Find out why you need to clean your email marketing list and learn how you can ensure success for your future emails. If you have any questions about the importance of double opt-in and how to best use it, feel free to reach out to us directly at

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