To adopt a double opt-in subscription policy, email marketers ask individuals to provide their email address to be added to an email list, then require the new subscriber to take action via a confirmation email. This second step ensures new leads are real, rather than a misspelled or fake address. It’s a simple way to reduce bounce rates, improve deliverability, and proactively maintain list hygiene.

What is double opt-in?

The double opt-in process helps marketers filter out bad email addresses and protect their sender reputation. If someone provides their email but doesn’t click the confirmation link, they won’t be added to the email list. This better ensures you won’t send to addresses that won’t open your emails, because the recipient has expressed active interest in the content by engaging with it, improving deliverability.

The double opt-in is a default feature that you’ll find in your marketing automation platform. When designing the opt-in form, there should be a checkbox to add a confirmation email. If you uncheck, it will auto-confirm everyone who fills out the form, whether the address exists or not (single opt-in).

The confirmation email sent to new subscribers should be simple:

• Subject Line: Examples: Confirm Your Subscription / Almost There… / Response Required: Email Opt-in
• Button/Call to action: Example: Confirm my subscription
• Body text: Example: If you received this by mistake or you don’t want to subscribe, please ignore this email.

Double opt-in vs. single opt-in

There are exceptions where single opt-ins can improve your email marketing campaign. Here are some examples:

• Your click-through rate is already above average
• Your goal is fast email list growth (not a great idea for deliverability)
• You have a high-converting ecommerce store
• Your form requires more fields than name and address

Single opt-ins can work as long as users can easily find the unsubscribe button. However, if you want engaged subscribers who open and click on more emails, double opt-in is essential.