As part of the CAN-SPAM Act, you must obtain permission from a user before emailing them. How you obtain their permission, via single opt-in or double opt-in, is a question each business must decide for themselves.
Perhaps you’ve already answered this question, but now, as you are conducting your quarterly email audit, you find yourself wondering if you’ve made the right choice.
The short answer is that it’s a personal choice. In fact, it’s a choice that might even change over time.
To help guide your decision, we’re going to review the pros and cons of both options and share a bit of our industry insight.
What is Single Opt-in?

The single opt-in method is a subscription path that allows users to become subscribers immediately by filling out a single form and checking an agreement box.
By completing these steps, the user is giving permission to be added to a marketing email list.
This single-stepped process does not require the user to confirm that it was, in fact, them who requested to register for your newsletter or be added to your marketing email list.
This method does allow you to engage with users immediately, but it does come with a few drawbacks as well.
Pros of Single Opt-in
Following the single opt-in method offers several positives:
- It’s a quick and painless experience for users
- It’s a fast way to build your email marketing lists
- Provides the opportunity to engage users, with a promotion or discount, quickly — while you know they are interested, online, and ready to engage
Cons of Single Opt-in
Believe it or not, even something as beneficial as a single opt-in strategy is, there are a handful of drawbacks you should keep in mind:
- Lower email deliverability rates and higher hard bounce rates than you’ll see with email lists created using the double-opt-in method
- Statistically speaking, email lists created with single opt-in methods have lower engagement and email open rates
- The single opt-in process leaves the door open to harassment or misuse by competitors or others who sign-up for your emails but then report you as spam to various ISPs (this type of activity could impact your email sender reputation)
- It’s easier for users to enter a fake email just to gain access to your premium content
What is Double Opt-in?

The email double opt-in process requires a user to complete the form and check the box, just as they do in the single opt-in process, but they then have to click a confirmation link or button that is sent to their email address.
When following this process, the user cannot be added to your marketing email list until they have clicked the link or button, officially confirming their permission.
Pros of Double Opt-in
This more cumbersome process has several positives:
- You are less likely to receive spam complaints from users receiving your emails
- Your emails are less likely to bounce and your email open rates are likely to be higher
- The email addresses on your list will be of a higher-quality nature
- It’s harder for fake emails or competitors to be added to your list and then successfully report your emails as spam (you’ll have a record that you can provide to ISPs if you’re sender reputation is called into question)
Cons of Double Opt-in
I wish we could tell you that choosing the double opt-in method was easy and straightforward, but it’s not. Unfortunately, there are a few drawbacks:
- Your email lists will take a bit longer to grow
- Younger users are less likely to check their email addresses as often as users from the Baby Boomer and Generation X groups
- Users who sign-up via double opt-in expect more, so if you don’t provide engaging content on a consistent basis, you’re more likely to lose their attention
Keep in mind, you can always start out with a single opt-in method and then switch to a double opt-in process as your list or content offerings grow.
No matter which option you decide to go with, make sure you keep your list up-to-date by conducting an email list audit every quarter.
Want to see how the MailMonitor suite of tools can help your business master email deliverability and improve your overall marketing email strategy? Contact us and request a demo!